Blitz,
Best of luck in your interview. You've gotten a lot of good advice. I think practicing is good, but don't make your answers sound rote. As a guy who's conducted a lot of interviews, here's what I look for during the process:
The individual is well groomed and appropriately dressed.
Gives a good, firm, short handshake.
Speaks clearly and conversationally, this is not the time to drag out the thesaurus.
Keep your answers short and on point and as previously said, be sure to listen and understand the question, but don't be afraid to ask the interviewer to clarify the question if it was unclear.
Don't use jargon or tech speak unless you get asked questions in that manner; make sure you use terms correctly.
Make sure your CV and your oral responses jive. I'm always looking for discrepancies between what the piece of paper says and what the person says.
Be confident but not boastful; if you haven't done a particular job or skill before say so, but be sure to give examples of how you've learned on the job.
Honesty is best, but don't put yourself down.
Please, please, don't ask "How will this job help me get my next job?"
Remember that there's a reason you are being interviewed. They have a need and want to see if you can fill it. You need to make that decision an easy one for them by showing them that you can make their problems go away.
Finally, make sure they know that you want work not a job. You want to make a contribution to the organization and want to be part of their success; you don't want them to make you successfull.
When I hire people it's because they have both the technical and social skills to further the purpose of my company which is to further the purpose of my clients. If you can demonstrate that attitude to the interviewer you'll have a big advantage over others.
Again, good luck and go get 'em!
Andy