Congratulations on your brilliant results
It will take off a lot of pressure next year.
And it's honestly personal preference, look at your topics, flick through textbooks, look at past exam papers and get a feel for the spec.
I found Psychology more stressful to revise, too many facts and figures and names, and more scientific *which isn't really me
* I enjoyed it, but I was definitely very worried about this and found it harder.
Sociology, although the amount of information is huge, I found that if you start early, it's not too much of a problem. My teachers didn't leave enough time for Unit 4 but I realised this and done a lot at home, and when it came to revise I was more confident. The exam wasn't hard, I didn't think, if you know how to debate and 'get' the theories etc, it's not too bad at all, just a lot to remember, that's all
God that was a ramble haha, hope it helped a little bit
Beliefs I loved, I found it easily accessible to everybody, really interesting and there isn't much at all compared to Unit Four, so if you literally ACE that unit, you will only need to get a low B/C in order to get an A overall (like me haha). Just make sure you have a good textbook, this first one here is amazing, and there's the website for it too
http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=sociology+a2+aqa&x=0&y=0http://www.sociology.uk.net/a/Start.aspx#page|181