hiya, in terms of chemistry revision my favourite thing for learning definitions and other chem stuff is definitely flashcards. i make mine on my phone on an app called cram. its also computer compatible. id really recommend it, its especially good as i always have it with me, so i can get in a quick 10 minutes on my bus journey to and from college!
otherwise i recommend past papers, and also youtube revision vids. theres a channel called E rintoul on youtube, he posts lots of chem revision vids. i usually watch one of these and then go into past paper questions.