[ethagnawl]

Regarding usage, you should start with the built-in vimtutor tutorial (separate binary which was most likely installed alongside vim). From there, read the manual and start looking at resources like vimcasts.org, /r/vim, _Practical Vim_, etc. _Learn Vimscript The Hard Way_ is also a great resource, but heavy on Vimscript, which you may or may not need on a regular basis. I'd argue it's worth taking a crash course so that you can try to debug third-party plugins or write your own. Really, though, the best way to learn is to jump in with both feet and search for solutions when you want to do something that you don't know how to do.

As for "tweaking" Vim, I'd suggest checking out open source vimrcs, like ThoughtBot's or Steve Losh's. You should also browse vim.org/scripts and check out plugins by people like Tim Pope and Junegunn. I can't think of any at the moment, but I know I've seen analogues to ruby-toolbox.com and clojure-toolbox.com which index plugins and let you search by topics and are a little more curated and user friendly than vim.org. You may also want to consider an opinionated Vim distribution (Janus, Space Vim, etc.), which comes with non-standard .vimrc settings and plugins.