The Comprehensive TeX Archive Network is the place to get materials related to the TeX typesetting system.
You can learn about TeX, LaTeX, and friends. This introduction will help you start using this system for your documents. It includes links to the most popular free software, which will give you all of the TeX that you will ever need.
You can look for what you want in a number of ways.
If you have developed some TeX-related materials then you can send it to either the Dante or Cambridge CTAN sites.
CTAN has a
set of mirrors,
sites around the world that copy their holdings and then offer
them to nearby TeX users.
For instance, you may notice that clicking on links like
"http://mirror.ctan.org/macros/latex/contrib"
redirects you to mirror near to you.
So a simple way to help out is to make your links have this form.
(If you could
be a CTAN mirror that'd be great.)
You can make a less taxing contribution by donating to offset expenses — small efforts add up!
I hope you find that these pages useful in your TeX-ing. — Jim