Don’t get me wrong, Vim is very powerful and well worth knowing if you’re going to spend any time at all on the command line, but I’m far from an expert. You could read the man page, sure, but Vim is one of those things you need to learn by using it.
Here are two resources, the first platform-independent.
On Linux, you can also just type in
vimtutor on the command line. If you get an error and you didn’t mistype the command, you’ll probably need to install a couple of packages. On Ubuntu, run the following:
sudo apt-get install vim vim-runtime
Now go learn some Vim.