Here you can find information on existing TeX packages, etc. For instance, you can find style files to format your paper according to the requirements of various journals. You can also find explanatory documents like the one outlining techniques for putting graphics into your document.
If you know the name of a file that you need, type it into the search box below and you will get a link to all the files of that name on CTAN.
Graham Williams has compiled an amazing catalogue of information about TeX, LaTeX, and associated topics, including TeX-related home pages and a wealth of other information. You can do a keyword search on this document.
These searches set a cookie to remember your choice of “archive copy to use”. To unset the cookie (for example, to choose a new archive), submit an empty search.
These may help you find what you are searching for. They are the links given most often as answers to “Where can I find information on ...” questions.
If you can't find what you need in any of these, try a search of past postings to the news group comp.text.tex or the mailing list texhax. One place where you can do that is Google groups, texhax at the TUG site. If you are still puzzled, try posting to comp.text.tex via Google groups, or to texhax via ordinary mail (you can subscribe to the group at the list info page).
This page maintained by Robin Fairbairns (revised 2006-January-21).