PLO8 is a good game if you're willing to be a bit creative, and quite profitable to play online. Holdem bankroll requirements are adequate for PLO8.
A good start is Ray Zee's book on Hi/Lo split games, though it is somewhat outdated for today's PLO8 games. But it give you a strong foundation in Hi/Lo games generally that you can build off.
http://o8poker.com/ is a decent site, made by an old poster here called gergery. He often wanders off into stories of his homosexual lifestyle and fetishes, but when he stays on topic he gives valuable advice.
Searching old threads is a great way to go as well. They're probably in the archives by now, but Ribbo and Wintermute had some good discussions a while back.