What is a good answer for "What is your weaknesses"?
"Blondes"
Any general tips, do's and don'ts would be greatly appreciated.
Try not to be too nervous. Get talking and you should relax. Remember that you are there to sell yourself, so make sure you talk, and not just let the interviewer do all the talking. Listen to what you are asked, and answer the question (not some other thing that wasn't asked). Talk about the things that you have done in the past that you are proud of, and the kind of person that you are. They will not just be looking for a person with all the paper qualifications, but also a person that will fit in and can learn to do the job, so you must show your personality as well as your skills.
Do a bit of research on the business, find out what they do, who their partners are, and a bit about their world. Think up some questions about the job and where it can take you. Don't say anything negative, either about yourself or any previous jobs/people/whatever. Anything you do say (like your weaknesses question above) should be tempered with good things that will mitigate any downsides. You want to come across as positive and enthusiastic.
This is basically a snapshot. Unless they give you some formal tests, they will expect that you can do the things you say you can do (unless they think you fibbed on your application forms), and want to find out what kind of person you are. They will probably ask some questions to make sure you haven't exaggerated on your resume, but it's an opportunity for them to find out what sort of employee you'll make, and you will have a limited time to give them a feel of who you are. Just try to relax and enjoy it, you will come across much better.
Interviews are something that you get better at with practice, and there's not much to do other than to keep going to them until you get the job you want.
If they do any psychometric testing, just be completely honest. The tests will show if you are fibbing.