Hi Phonemum:
Some of us discussed end of year 7 exams earlier and have already been discussing our views here: www.mumsnet.com/Talk/secondary/2387696-End-of-Y7-EXAMS
DD1 had hers before half-term and fortunately has done really well so our strategy of systematically going through the exams and working out what revising was needed (and when there wasn't much you could do - i.e. English/ Maths/ Art in DD1's case) so she could focus on subjects that required more effort (MFL/ Science in DD1's case).
Some of the teachers sent home little notes with some pretty heavy hints about what would be on the exam - so it's worth asking about that. I just did by chance and DD1 produced a note from the MFL teacher which was pretty specific and really helped us focus revising for this exam.
BBC bitesize and things like language websites can be really useful - practice that bit that is tricky, play games that help you review information, take practice tests, etc....
If your school has revision sessions between exams - you can also use these for revising less demanding/ stronger subjects - i.e. for Art DD1 knew she'd be asked some terminology so she reviewed that just before the test - but she also knew that the main part of the test was a still life drawing task. DD1 felt there really wasn't much she could do before the English/ Maths exams - which were basically old GCSE papers. She had practice papers for homework the week before exams and worked hard on those, but otherwise that was it for revising. Her real focus was vocabulary in MFL & Science - a real weakness for her. She put in a lot of time in areas she knew would be tested and that extra practice seems to have helped.
HTH