During a phone interview, programming test, and interview, the chances are that you’re going to get asked a load of questions. Many of the questions you’ll be asked are general programming questions, perhaps dressed up with a game related theme. Doing a quick search for “programming interview questions” yields a bunch sites which round up the types of questions you get asked.
Reading and answering a few questions probably isn’t going to suddenly make the interview process a cakewalk, but it can show you some areas to practice and can give you an idea of the type of questions you’re going to be asked. Beyond standard interview questions, in a games interview you’ll likely also get asked questions about 3D math, and lower level operations like memory allocation, pointers, bitwise operations, and hardware and operating system concepts.
One more thing. It's easy to read a question, read the answer, and fool yourself into thinking you'd be great at answering. Put a bit more effort into it, write your answer out, talk out loud as if you were talking to an interviewer. You might find that the answer is harder to write down than you think, or that you've forgotten your impressive vocabulary of cromulent words. Another good idea is to code it up and make it work - if you've not written a linked list class in a while, an interview is a pretty rough place to re-learn it. This is why I recommend working on demos, and keeping on coding while you go through the interview process.