Recommendations for a good vi reference?
This is the best to keep in your desk, full of coffee works great :-)
(source: thinkgeek.com)
The Mug of Vi References
I also like the VI Editor Pocket Reference book.
A good cheat sheet you can print out is here: http://www.viemu.com/a_vi_vim_graphical_cheat_sheet_tutorial.html
Learning the vi editor by Arnold Robbins and Linda Lamb
A little companion for quick reference (by A. Robbins) is also available.