A lot has been said about different kinds of math resources here in MO. To mention a few:
Most helpful math resources on the web
Undergraduate Level Math Books
So having benefited a lot from free resources on the net, I thought it would be more helpful if I shared my list of important sites and learned from others, too.
Here are my list of sites providing free math resources. Some of them are file hosting and sharing sites and others may need registration.
1. Math Online Recently launched by Andrea Ferretti
4.2020ok Directory of FREE Online Books and FREE eBooks
7.Scribd is a social publishing site, where tens of millions of people share original writings and documents. Scribd's vision is to liberate the written word.
8.4shared.com - free file sharing and storage
My question here is to find more free resources sites possibly specializing in a given branch of math. Please specify a direct link anf whether registration is required.
- PS: One technique I use is to google my desired file with its file name and type as in "Elliptic curves pdf"(which returns a list of pdfs on elliptic curves) or "Random matrices doc" (for word document search) and "Ramanujan history ppt"(which returns a list of presentations or slides).
You may also suggest such search techniques.