How can I get a head start to a level CHEMISTRY and MATHS????

I'm not too sure how I can get a good head start during this summer holiday as I have lots of time. I don't know what revision guides are good. I don't know if cgp is good as it just seems a bit cartoonish and if there are any other alternatives ,Help!

All comments appreciated

For chemistry all I would recommend doing is molar calculations and learning all the formulas. They'll teach you the rest.