I get a lot of inquiries about interviews for testing and QA positions, as well as about testing questions for software developers. From my perspective, I always look for two things, particularly - general smartness and industry experience. Testing in UI world is very different from testing Video Games and if I need someone to start on the project right a way, I would ask specific questions to get the sense on the candidate’s experience in the specific field.

I also, always recommend to know as many testing, automation, measurement and etc. tools as possible.  Requirements vary from company to company and sometimes your resume might be tossed just because recruiter didn’t see some tool name in your keywords. At the same time, this can greatly help during on site meeting, then interviewer would ask if you ever used tool X. Even if you didn’t but you know what does it do, you always can answer something like “No, but I’ve used tools A, B and C which are very similar to X and I am confident that getting up to speed with tool X would take literally no time for me”. 

Another good approach would be to research company background and know upfront which testing tools they are using. As an example if you are interviewing with company which is using Visual Studio as development IDE, I would encourage to be familiar with VSTS (http://msdn.microsoft.com/en-us/library/ms182409.aspx) and all set of Microsoft testing tools. Even if they are using different testing framework this knowledge would allow you to start intelligent conversation on pros and cons of each system.

For .NET Testers the good really check would be looking on:

 NUnit - NUnit is a open source unit-testing framework for all .Net languages.

Visual Studio Team Edition for Testers -  Visual Studio Team Edition for Testers includes a suite of test tools that are integrated closely with Microsoft Visual Studio; they work not only in their own testing framework, but also within a larger framework of software life cycle tools.

Test Run - Lightweight UI Test Automation with .NET

Pex - Automated White box Testing for .NET

NCover - Code Coverage for .NET Developers

Testing .NET Application Performance

Below is my compilation of most common interview questions for tester/QA position:

Software Testing Basics

What is the QA process?
How do you train another QA engineer?
How do you start your QA if there are no system requirements?
What kind of PC games you like most? Why?
In which Software Life cycle phase does testing occur?
Can you explain PDCA cycle and where does testing fit?
What is the difference between white box, black box and gray box testing?
Define Defect?
What is the difference between Defect and Failure?
What are the broader categories of defects?
What is the difference between Verification and Validation?
How does testing affect risk?
Does Increase in testing always mean good to the project?
As a manager what process did you adopt to define testing policy?
Should testing be only after build and execution?
Are number of defects more in design phase or coding phase?
What kind of inputs do we need from the end user to start proper testing?
What is the difference between Latent and Masked Defect?
A defect which could have been removed during initial stage is removed in later stage how does it affect cost?
In testing can you explain the concept of work bench?
What’s the difference between Alpha and Beta testing?
Can you explain the concept of defect cascading?
Can you explain how one defect leads to other defects?
Can you explain what is Usability testing?
What are the different strategies of rollout to the end users?
Can you explain requirement traceability and its importance?
What is the difference between Pilot and Beta testing?
How will you do a risk analysis during software testing?
How do you conclude which section is most risky in your application?
What does entry and exit criteria mean in a project?
On what basis is the Acceptance plan prepared?
What’s the relation between environment reality and test phases?
What are different types of verifications?
What’s the difference between Inspections and Walkthroughs?
Can you explain regression testing and confirmation testing?
what do you mean by coverage and what are the different types of coverage techniques?
How does fundamentally a coverage tool work?
What is configuration management?
Can you explain the concept of baseline in software development?
What are the different test plan documents in project?
How do test documents in a project span across software development life cycle?
Can you explain inventories?
How do you do Analysis and design for testing projects?
Can you explain calibration?
Which test cases are first written white boxes or black box?
Can you explain Co-habiting software?
What different impact rating’s you have used in your project?
Can you explain what a test log is?
Explain SDLC (Software development Life Cycle) in detail?
Can you explain waterfall model?
Can you explain big-bang waterfall model?
Can you explain phased waterfall model?
Explain Iterative model, Incremental model, Spiral model, Evolutionary model and V-Model?
Explain Unit testing, Integration tests, System testing and Acceptance testing?
what’s the difference between system and acceptance testing?
Which is the best model?
What group of teams can do software testing?

Testing Techniques

Can you explain boundary value analysis?

How do you debug SSH?  
What is BV in software testing?
Can you explain Equivalence partitioning?
Can you explain how state transition diagram can be helpful during testing?
Can you explain random testing?
Can you explain monkey testing?
What is negative and positive testing?
Can you explain exploratory testing?
What exactly are semi-random test cases?
Can you explain the concept of orthogonal array?
Can you explain pair-wise defect fundamental?
Can you explain the concept of decision tables?
How did you define severity ratings in your project?

CMMI

What is a Software process?
what are the different cost element involved in implementing process in an organization?
What is a model?
What is maturity level?
Can you explain the concept of process area in CMMI?
Can you explain the concept of tailoring?
What is CMMI and what's the advantage of implementing CMMI in an organization?
what’s the difference between implementation and Institutionalization?
what are different models in CMMI?
Can you explain staged and continuous models in CMMI?
Can you explain the different maturity levels in staged representation?
Can you explain capability levels in continuous representation?
which model should we use and under what scenarios?
How many process areas are present in CMMI and in what classification do they fall in?
What the difference between every level in CMMI?
what different sources are needed to verify authenticity for CMMI implementation?
Can you explain SCAMPI process?
How is appraisal done in CMMI?
which appraisal method class is the best?
Can you explain the importance of PII in SCAMPI?
Can you explain implementation of CMMI in one of the Key process areas?
Explanation of all process areas with goals and practices?
Can you explain the process areas?

Six Sigma

What is six sigma?
Can you explain the different methodology for execution and design process in SIX sigma?
What does executive leaders, champions, Master Black belt, green belts and black belts mean?
what are the different kinds of variations used in six sigma?
Can you explain the concept of standard deviation?
Can you explain QFD?
Can you explain FMEA?
Can you explain X bar charts?
Can you explain Flow charting and brain storming?
Can you explain the concept of fish bone/ Ishikawa diagram?

Metrics

What is meant by measure and metrics?
Can you explain Number of defects measure?
Can you explain number of production defects measure?
Can you explain defect seeding?
Can you explain DRE?
How do you measure test effectiveness?
Can you explain Defect age and Defect spoilage?
What is code coverage?
What code coverage tools do you know?
How would you approach measuring JavaScript code coverage?
What is industry standard for code coverage numbers?


Automated Testing

What automating testing tools are you familiar with? 
How did you use automating testing tools in your job? 
Describe some problem that you had with automating testing tool. 
How do you plan test automation? 
Can test automation improve test effectiveness? 
What is data - driven automation? 
What are the main attributes of test automation? 
Does automation replace manual testing? 
How will you choose a tool for test automation? 
How you will evaluate the tool for test automation? 
What are main benefits of test automation? 
What could go wrong with test automation? 
How you will describe testing activities? 
What testing activities you may want to automate? 
Describe common problems of test automation. 
What types of scripting techniques for test automation do you know? 
What are principles of good testing scripts for automation? 
What tools are available for support of testing during software development life cycle? 
Can the activities of test case design be automated? 
What are the limitations of automating software testing? 
How to find that tools work well with your existing system? 
Describe some problem that you had with automating testing tool. 
What are the main attributes of test automation? 
What testing activities you may want to automate in a project? 
How to find that tools work well with your existing system? 
What are some of the common misconceptions during implementation of an automated testing tools for the first time?

Testing Concepts

How you are breaking down the project among team members?
Can you explain TPA analysis?
Can you explain in brief Function points?
Can you explain the concept Application boundary?
Can you explain the concept of elementary process?
Can you explain the concept of static and dynamic elementary process?
Can you explain on what basis does TPA actually work?
Can you explain step by step how did you do estimation for black box testing?
How did you estimate white box testing?
Is there a way to estimate acceptance test cases in a system?
What is a test suite?