DocJohn, please post those recommended websites, it's quite alright. I don't know what Continent you're on, but the Continental resonator guitars are available in the U.S.

Dick, the Regal you have - does it have a spider bridge arrangement (cone pointing down, like Dobros) or a biscuit bridge (cone pointing up, like Nationals)?

I find spider bridge ones are louder and clearer and more suited for bluegrass than the biscuit bridge ones, which have more of a garbage can clangy blues sound. What do you think?

Dick, the tunings Murray posted are right on. The G tuning is the one most commonly used for slide blues work. The D and E tunings (they have the same string relationships) work for slide, but are also often used for fingerpicking tunes without a slide - Mississippi John Hurt used this a lot (check out "Payday," which is a great creative springboard that will have you noodling around in D or E right away).
Standard Dobro tuning, which is used for bluegrass work is (going from bass string to treble): GBDGBD. This is for regular Dobro playing rather than bottleneck slide, that's with the guitar's face looking at the ceiling, playing with a bar held in your hand (like a "stevens steel") rather than a hollow tube on your finger.

Mark