Features and usage are summarized on the homepage.

This script will prompt for confirmation before it does anything:

ruby -e "$(curl -fsS http://gist.github.com/raw/323731/install_homebrew.rb)"

Afterwards, install Xcode.

Indeed, you can. Refer to our complete installation instructions.

Okay then, but please note this installs Homebrew as root and we recommend against that.

curl -LsSf http://github.com/mxcl/homebrew/tarball/master | sudo tar xvz -C/usr/local --strip 1

Before installing you can browse the Formula folder on GitHub.

After installing, you can use brew search to find packages or brew server to browse packages off of a local web server.

The wiki is your friend.

I'm Max Howell and I'm a splendid chap.