Need help getting started with bittorrent

[Kevin O'Gorman]

I've got transmission-gtk up.  I can start it.  I have no idea how to use it.

I want to download some isos to install 12.04.  I have some other
stuff that I would not mind offering.

I've tried looking for documentation, but all I find is statements
that this is easy, plus sites on the protocols, developer stuff and so
on.

I'd really like a quick step-by-step for getting
xubuntu-12.04-desktop-i386.iso.torrent for starters.

-- 
Kevin O'Gorman, PhD