English Literature - To Kill a Mockingbird
http://www.litcharts.com/lit/tokillamockingbird/: really useful summary of the whole book, including a downloadable chart (which you could print out and put up in your room!). There's also an iphone app to help you revise.
http://www.sparknotes.com/lit/mocking/: another helpful site, with character analyses, summaries and details of important quotations.
English Literature - Poetry
Try visiting this site (Englishbiz.co.uk) to read a clear guide to how to understand and analyse a poem.
http://www.scribd.com/doc/25781178/What-Do-You-Call-It-When: a guide to the technical terms used when writing about poetry, with specific references to the poems from the GCSE 'Identity' collection.
If you click here, you will find all Mr Burn's poetry revision materials on www.scribd.com.
English GCSE - Writing Skills
http://www.englishbiz.co.uk/: lots of excellent resources and help sheets, focused on GCSE examination tasks, as well as links to other websites.
http://www.bristol.ac.uk/arts/exercises/grammar/grammar_tutorial/page_01.htm; a site run by the University of Bristol, which provides explanations of punctuation and grammar, as well as on-line exercises with answers. Well worth spending time working on.
http://theoatmeal.com/, as well as offering invaluable advice on how to tell if your cat is out to kill you, has created some fun, light-hearted comics to help you understand some of the knottier corners of English: How to use a semi-colon, How to use an apostrophe.