Reddit mentions of Edexcel as Government & Politics Student Unit Guide: People and Politics

For Literature, read around your set texts. Critical interpretations are essential and it's never too early to start gathering them. If your school has them, there are magazines called English Review and e-something or other that are useful and aimed at A-Level students. Otherwise just look online. They're worth marks in the exam if you can reference so-and-so's critical interpretation and they'll help you understand the texts.

Also, revising quotes. You'll need to know them by memory so whenever you're reading, be thinking about killer quotes. If you think you might end up writing a lot about feminist interpretations of the text and there's a line that supports that, highlight it or something.

Don't watch the films. My mate kept having to remind himself that Lord Henry doesn't actually have a daughter, that was made up for the film. It'll only narrow your interpretation of the text and maybe mislead you entirely.

Once you've read all the texts for an exam, start asking your teacher to mark your practice essays. If you have more than one teacher, maybe vary it up who you hand your essay in to.

If there's more than one English class, talk to people in the other class. Because you can go in so many directions with a text there will inevitably be differences in what the two classes discuss and learn about. You'll know things they have no idea about and vice versa. Also, talking about texts is really fun.

Don't rely on them, but don't be ashamed of going to York Notes if you're a bit lost. They're generally worth the money and can really help. With York Notes, I found out that I didn't actually know what was going on in 'Tis Pity She's a Whore at all. Like, that text is a mess. Yeesh. If you get set it at any point, feel free to send me a PM. Jesus.

Look at past exams now and see what you're in for. If there's always a question about a specific character, you'll need to revise every character. Past exams are also good for finding out what sort of themes you should be looking at, although it won't make a comprehensive list by any means. Just nice to have.

For Politics... I don't know how I did well. Those thin little revision guides are magic and I had an incredible teacher. Lots of past paper questions - the politics spec I studied had been around for long enough that almost every possible question had come up. Make use of that.

Another thing, keep up with current political goings-on and keep a bank of evidence for whatever you might need to argue in an essay. Evidence is crucial in tying your arguments together and examiners like recent evidence as well as the historical context. You don't want to forget anything - start gathering. Like, apparently part of the Edexcel spec is "consensus and adversary politics". Right now, Labour and Conservatives are both spewing the same "Better Together" rhetoric about Scotland. That's cracking evidence of traditionally adversarial parties reaching a consensus for pragmatic reasons.

Again, reading a lot is good. Read the news from somewhere decent - BBC's alright, The Guardian's a good one. Read Owen Jones' The Establishment and How They Get Away With It for more on consensus. I'm reading it now, the chapter about how Thatcher brought a new consensus to replace the post-war consensus is fascinating and I would be highlighting the hell out of it for essays if I was still studying politics.

I think I was OCR for English and AQA for Politics, but yeah. Hope that all helps!