John Baez, at This week’s finds in mathematical physics points to a large number of online resources:
At least around here, Christmas seems to be all about buying stuff and giving it away. Giving is good. But I think gifts have more soul if you make them yourself. This is one of the great things about the internet: it lets us create things and give them to everyone in the world – or more precisely: everybody who wants them, and nobody who doesn’t.
In this spirit, here’s a roundup of free books on math and physics: gifts from their authors to you.
There are nearly thirty links that Baez provides; even though some of the later links are for very specific areas of mathematical physics, there are several for general mathematics and physics. Take a look!