Quote Originally Posted by MadMojoMonkey View Post
Well, my bias is clear, but I'd suggest getting a nice, thick, illustrated intro physics book.
I recommend physics as a starting point for all sciences, because I don't know of a science degree that doesn't require introductory physics.
It shouldn't be too hard to find used textbooks online.

Randall D. Knight - Physics for Scientists and Engineers is a good choice. It's available used for ~$20 after a brief google search, so practically free considering it's over 1,200 pages.

David J. Griffiths - Introduction to Quantum Mechanics is extremely well written, but does rely heavily on your background understanding of linear algebra and some other physics concepts.

Peter V. O'Neill - Advanced Engineering Mathematics is another one of my "always on the reading list" books. It's another huge compendium of a textbook, but it covers so much math that is put to regular use in any engineering field, like diff EQ and linear algebra.

Brian Bradie - A Friendly Introduction to Numerical Analysis will be extremely useful if you'll be using computers to gather and analyze data. The quirkiness of dealing with a discrete number system and not a continuous number line is interesting to unravel, and can sink your research if you aren't aware of the pitfalls.
All those books are like £50+. Which isn't much but it really puts me off. At teh same time stats and probability is probably (or maybe I'm misunderstanding) my weakest part as I never really did any.