The principles of slacklining are pretty simple, but I found that in practice they're a little fussy to set up. Nothing you probably can't handle with some trial and error.
One of the more useful pieces of beta a friend of mine gave me when he helped me set up a line was the ratio of untensioned line to the length of what you want to the final length to be. Otherwise you do a lot of trial and error when you've finished tightening it down and it's either too tight, or too loose and you have to redo it. I have it at home, I'll look it up.
As for gear, I just used about 7 carabiners, lot's of 1" webbing and a bigass come-along. I probably would haved saved time (but not money) if I went here: http://www.slacklineexpress.com/
. In general, there's a ton of good free info all over the web. It's a particularly good topic to Google.
it looks like a very interesting and tough sport and a good way to impress ladies.
So far, I have impressed no ladies - not even my wife. But that's probably just me....