Hey there! Am not planning on taking Maths/ Further Maths /Physics/CS A Level (clearly I use too many '/' too haha!) but as I've been looking for books to read around my future A Level subjects too, I have a general idea of what books you might want to look into. Whatever subjects you do, reading around the subjects means you can add more to your personal statement, so you can't really go wrong (especially with these subjects, as I'm assuming the average / clueless person like me! would wonder why maths is important in the real world etc. and you can distinguish yourself by reading into this).
I'm sorry I can't give you specific recommendations for books / podcasts / other resources given that I'm not doing the subjects (you'd probably have more luck with a Y13 doing their personal statements, or university goers ) but having a look on university recommended reading lists that list non fiction and even fiction books to read for your subjects could be a good idea. Many people recommend the Oxford Maths Reading List, but have a look for all your subjects.