TeX / LaTeX

Software

• TeXShop - Official Web Site 
• TeXLive - Official Web Site 
• TeXLive Documentation 

Organizations

• TeX Users Group (TUG)
• AMS LaTeX2e
• Comprehensive TeX Archive Network

References

• Learn by Example: LaTeX Tutorial
  compare the source code (tex, 29KB)
  and the compiled result (pdf, 206KB, 11 pages)
  Note that it is necessary to compile the source code twice for all references to be correct.
• The TeX Cookbook  (pdf, 132KB, 12 pages) Common mathematical symbols in TeX / LaTeX.
• A Simplified Introduction to LaTeX  (pdf, 2.55MB, 146 pages) If you want to read a book about LaTeX, this might as well be your first one.
• The Not So Short Introduction to LaTeX  (pdf, 2.07MB, 127 pages)
• The UK TeX FAQ - Your 371 Questions Answered   (pdf, 2.21MB, 220 pages)
  A Q&A list that originated when British humour met typesetting.
• A short description of the Theorem package of AMS.
• color  (pdf, 32KB, 2 pages) How to get text in different colors in LaTeX.
• exam  (pdf, 292KB, 63 pages) A fairly long description of the Exam package.
• TeXnik (LaTeX Tips and Tricks) from TUG
• The Comprehensive LaTeX Symbol List from CTAN   (pdf, 132KB, 105 pages)
• Wikipedia entry for: ,
• WikiBooks for: , ,