I took some lap steel lessons last summer from my teacher. He showed me the basics of the C6 tuning, which is your 'western swing' tuning. Its also great for blues and rock however- the pentatonic type stuff falls pretty naturally in that tuning. You do need to get specific lap steel string sets for that tuning however. I'm pretty sure Elderly.com carries them, and some tab and instructional books and videos as well. Cindy Cashdollar comes to mind.
Lap steel is really fun, very different than bottleneck. You also need a heavy solid bullet
slide, like a shubb.
Now that I can play lap just a little bit I can really appreciate what guys like Robert Randolph and Speedy West are all about on the pedal steel.
Deep!