If you are interested on doing it on the cheap have a look at http://www.linuxdoc.org there are loads of howto's and guides. Most are downloadable as well. Some are out of date but try the link for the latest version if it matters. If you find a topic you want to know more about a book often helps. I teach myself loads with books and online guides great fun
If you are rich I suppose you could just pay some one to teach you but as I'm not I haven't considered that.