What can I do to help me to prepare for my interview?

The best thing to do in the time before your interview is to try and relax. Once the interview date has been confirmed (usually around the second week of December), work backwards from that date to make sure you can do everything that needs to be done.

Firstly, look at the website of the college you are applying to. Most of them will have a section for interviewees which will explain the process for your subject, as each vary slightly. Some may have two subject-specific interviews, others will have a written test and some may have only one subject interview and a more general interview to see if you will fit into college life. There may even be mock interview videos and articles. If your college does not provide these, browse the faculty website or other colleges as these may also provide useful information.  

Secondly, make sure you know any books, articles or theories that you have claimed to have read on your UCAS Application and/or SAQ very well. You won't need to know them in minute detail, but be able to talk about them confidently. Academics will like it if you have your own views on the texts, and can draw original synoptic comparisons with the subject more generally.  Finally, keep up to date with the news. The person who is interviewing you is most likely to be your supervisor when you get in. They want to know you are someone who is interested in the world and that they can have a good chat with you! For this reason, I go back to my first piece of advice: don't panic! You already have the academic capabilities needed, or you wouldn't have got an interview! The main purpose of the interview is to see how well the dynamic works between you and the interviewer, you spend a lot of time with your supervisors so they want to know that they can get on well with you.  Good luck!