Theory and methods will probably be either about a theory, such as postmodernism, marxism etc, or about a method such as group interviews, observation, personal documents etc. However it could combine the two. It won't link to a specific context, unlike methods in context. If it's about a theory it will probably ask you to look at the theory's usefulness in understanding society in general. What it won't do is ask you to look at a theory's usefulness in understanding a specific topic such as education or crime. You may get a question which is more general or inbetweeny such as "Outline and explain two factors that affect our choice of research methods and topics to investigate" or you may get a more specific one such as "Outline and explain two ways in which Marxists challenge the Functionalist view of society today".
It could also be on one of three areas which are a bit more tricky, as they are completely new for the A2 year and weren't taught at AS level. These are:
Sociology as a science
Sociology and values
Sociology and social policy.
I'd suggest you make revising for these three areas your priority. Revise whic theories think sociology should try to be scientific (Marxism and Functionalism for some) and which think sociology shouldn't try to be scientific (interactionism). Also, whether sociology can follow the KUDOS principles that are applied to science, whether sociology and science are confined by paradigms (Kuhn's argument, if I remember correctly), and the difference between open and closed sciences which Realism points out.
Then revise the Functionalist view that sociology should aim to be value free, people like Myrdal who believe it should aim to be but in reality cannot be, Weber who argues sociology can be value free during the research itself but not before or after, and Becker who thinks sociology shouldn't even try to be value free because it has a duty to stick up for disadvantaged groups.
Then, reasons why sociology should or shouldn't try to influence social policy, and what obstacles it might face if it tries to influence social policy.
For the theories, make sure you have a good understanding of Functionalism and Neo-Functionalism, Marxism and Neo-Marxism, Postmodernism, the feminisms, Realism, Weber, Symbolic interactionism and a little bit about ethnomethodology and phenomenology as well, though you only need to know a small amount about the last two. Check which are macro, which are micro and which are structuration, and consequentially which research methods they all like to use. Check which macro theories are consensus theories and which are conflict theories. For the research methods, your revision of this will double up a bit with methods in context. Remember observation (covert or overt, participant or non-participant), interviews (group, structured or unstructured), documents and statistics, field experiments, laboratory experiments and open and closed questionnaires. Which ones are quantitative, which ones are qualitative and which ones are in the middle? What are some practical, theoretical and ethical considerations for each of these methods? If you can get all of this down, you'll be well on your way to some good answers.
Gosh it's hard! *wipes brow.*