Hey everybody. I?m trying to get started playing slide guitar (played reg. guitar about 9 yrs). I don?t really know anything about playing slide. I bought a couple of slides, but they?re only big enough to fit around my pinky (actually I can get them on the top half of my ring finger). I need some recommendations on string gauge (I think you need heavier strings, yes?) and where to actually wear slide, whether I should start playing in open tunings, etc? Are there any threads on this site or any other websites that could help me out?
thicker strings make your guitar louder and give more sustain so yes, and if youve got the time, rising your action helps with slide guitar too, i personally use a slide on my little finger though some people feel they get more control using thier ring finger
Most of the greatest slide players use it on their ring fingers. The usual counter to that style is that using it on your pinky allows you to use your free fingers to make chords and do "normal" melodies. However, the greatest players don't need their other fingers... they're good enough with a slide.

Yes, bigger strings are normal, higer action usually, too. But don't go too drastic. A common gauge set is 11-46 (I use 11-52s normally and with a slide). 10s and below are too thin and sound weak. Giving your guitar more action should be a thing done n moderation---you still want to be able to play without the slide and without having to redo the action every time you switch.

Common open tunings are E, D, and G. I prefer E, but that's just because I learned it first and know where the notes are. You just gotta play along to a lot of songs with slide and after even a few days, you'll be able to find the good notes in any key in any tuning.

Some guys to listen to:
George Thorogood (dirty rock and roller), Duane Allman (Allman Bros guy, dead), Warren Haynes ("replaced" the deceased Allman, still plays with the Allman Bros and also with his own band Gov't Mule), Derek Trucks (the next great player of our time; watch him and you'll see. Got to the Blues and Jazz forum and you'll find a lot of people raving over this kid's style. He plays alongside Haynes in the Allman Bros and also his own self-titled band), Elmore James.

Virtually every great guitarist is proficient with a slide, but those are the big names.
Looking for my India/Django.