To a newcomer like me, Vim's built-in help was less than worthless, since you pretty much need to know the Vim term for what you're looking up to find it. Googling around wasn't much more effective (there's a lot of garbage in the Wikia for Vim that comes up at the top of many searches).
In the end, I needed to read these two "gentle" introductions to Vim to even understand what it was all about:
http://stevelosh.com/blog/2010/09/coming-home-to-vim/
http://yehudakatz.com/2010/07/29/everyone-who-tried-to-convi...
…and then I needed a mostly-well-documented distro like Janus (https://github.com/carlhuda/janus) to ensure that my productivity wouldn't take a huge hit those first few weeks.
Some folks can probably go all-in cold turkey, but I needed the training wheels.