Interviews are a piece of cake. Firstly, try not to get nervous about it. I don't now, and it's mainly because it's the same thing they ask every time.
Have a couple of predefined answers ready to whip out any time you need them. An example of when you worked as part of a team, an example of when you made an effort to improve yourself or something you wanted to do.
Remember - the facts are already on your CV, so you don't need to go over them so much. You need to get across your personality and why they should pick you over someone else.
Why are you specifically suitable for the job? Not qualifications, they can see those. What you bring to it that someone else might not.
It's all common sense really. Almost anything you've done can be twisted to fit the kind of questions they'll ask. It's all about making it fit so it shows you in a good light. You're part of an online commuinity here, so there's a socialising and networking ability, the ability to get on with others. No thought involved in that one.
The basics:
1. Be on time. Duh
2. Don't accept a drink if they offer one. If you're nervous, this is a disaster waiting to happen. You'll fidget with the cup, or you might end up dropping it or something.
3. Don't go to the toilet before the interview. You don't want them to end up waiting for you, and you certainly don't want them to see you coming out and then have to shake your hand.
4. Don't fidget in the interview. If you notice yourself doing this, clasp them in your lap. I talk a lot with my hands, so this isn't such a bad one for me, but I do have to try not to bite my nails in these situations.
5. Find out a bit about the company before the interview so you can ask them at least one question when they ask. And do not ask about pay at that point. If they don't cover pay in the info they give, ask about it on the way out the door, as if it's just crossed your mind. You don't want them thinking that's all you care about (even if it is).
Hope some of that helped. Good luck