Vim: How to Install Airline?

Vim: How to Install Airline?

I'm just getting started with Vim. It's a fun experience, but I've found
it to be kind of overwhelming. I'm trying to get this plugin installed,
vim-airline, but I'm having a lot of trouble. The Installation section on
the Github page simply states:
copy all of the files into your ~/.vim directory
Presumably, this means download the .zip, extract it, and copy all of
those files into ~/.vim/. I did this, but Vim just starts up like normal,
and running
:help airline
just gives:
Sorry, no help for airline
I assume that this means it isn't getting installed. Also, the statusbar
remains the same. I'm new to Vim and would really like to get this
working. Thanks in advance!
EDIT: I also tried putting the files into /usr/share/vim/vim73/. No dice.