My last math was in high school, and I'd like to spend more time learning in the coming year. I often read research papers, and the biggest challenge for me is the notation. I can understand the stuff around set theory, and a bit of the sigma notation here and there.

What I'd like is a proper introduction so I can start learning properly. Any book one would recommend? I'm keen on buying if it's not on the Springer list. Thanks in advance.

'What Is Mathematics?' Second Edition by Courant, Robbins & Stewart[0] is a great introduction to Mathematics in general (And covers most of the main fields), but also (iirc) is good at describing the notation used. As well as that I find Wolfram Alpha[1] and Math As Code[2] good at describing some pieces of notation.

Other introductory books I've found very useful are the 'Dover Books on Mathematics' introductions series, I've found their graph theory[3] and topology[4] books rather concise and clear to read -- to my knowledge they're availible at archive.org in the collection 'folkscanomy mathematics'[5].

[0]: http://www.amazon.co.uk/Mathematics-Elementary-Approach-Meth...

[1]: https://www.wolframalpha.com/

[2]: https://github.com/Jam3/math-as-code

[3]: https://archive.org/details/IntroductionToGraphTheory

[4]: https://archive.org/details/IntroductionToTopology

[5]: https://archive.org/details/folkscanomy_mathematics