There are many resources out there to help you learn and master Vim. Here are some of my favorites:
The book Practical Vim, by Drew Neil is truly great. I think it’s required reading if you really want to improve your Vim-fu. Drew also does screencasts at http://www.vimcasts.org.
If you want to learn more about Vimscript check out Learn Vimscript the Hard Way, by Steve Losh. It’s a great resource for anyone that wants to write Vim plugins.
I wrote a flashcard-style learning program for Vim called Vim Genius. You can play it for free at http://www.vimgenius.com.
http://vim.wikia.com has quite a bit of information. You will surely come across this site if you do any Googling about Vim.
Here is a great image of a keyboard overlaid with all the Vim commands and their actions: http://www.viemu.com/vi-vim-cheat-sheet.gif
And of course there’s always StackOverflow, and your old buddy