Slide guitar is a technique for creating a vocal, singing sound out of your guitar. Many lead guitar players like to play slide guitar, especially in blues. Get a brass or slide out and get started learning more about the art of slide guitar.
Some of my slide players I recommend listening to would be: Elmore James, Muddy Waters, Son House, Sonny Landreth, David Lindlay, Ry Cooder and Johnny Winter, great players. There are of course may more. I like players who use their right hand fingers for dynamics and added "rhythmic grooves". Derek Trucks is another exceptionally fine player, with a vast musical vocabulary. He has impressed me a lot.
I usually tune my guitar to E major, although I occasionally use a slide with normal tuning, but that I find that hard to do well. E major works well for many situations, and is probably the tuning that is best to start out with.
I use a my Squier '51 for slide. I like the tones of this guitar, and with a slide it sounds really cool. Sonny Landreth uses strats, and he's got the best slide tone in the world, in my opinion. Just set your action real high, and adjust the bridge saddles so all the strings are at even height - there's no arc that follows the fretboard contour.
I started playing with a glass slide on my Strat, but it was a thin one, and it didn't work out so well for me. I switched to a real heavy Dunlop Brass Slide, and it works much better for me. It's important for me to use a heavy slide - it makes it much easier get good tones and there's less rattle and noise.
I prefer to use a tube amp when playing slide. Some overdrive is often cool, and with a good amp you can often get a nice clean tone by just rolling down the town knob a bit. A good fuzz tone is great fun to play with (even without a slide!). I also like to use a bit of delay on my sound. It makes the notes and chords float together nicely.