Features and usage are summarized on the homepage.
Indeed, you can. Refer to our complete installation instructions.
Alright then… as long as you know what you are doing:
sudo chown -R $USER /usr/local curl -Lsf http://github.com/mxcl/homebrew/tarball/master | tar xvz -C/usr/local --strip 1
The wiki is your friend.
I'm Max Howell and I'm a splendid chap.