Vim - Cheat Sheet (essential commands)
Following is a link to a cheat sheet of some useful and most often used Vim commands. This Vim cheat sheet isn't trying to include all the Vim commands in the known universe, but should list the most essential ones.

Vim - Tutorials
http://www.apmaths.uwo.ca/~xli/vim/vim_tutorial.html
http://www.unb.ca/documentation/UNIX/tips/vim/
http://www.viemu.com/a_vi_vim_graphical_cheat_sheet_tutorial.html