#2
i know there are some videos, search videos on yahoo to show ya, or youtube.com

Its like playing a chord, but as you sweeping down, you finger each string individually, as your are stroking down.

its kinda hard for me to think of an easy way to describe it. Its a very advance guitar technique basically if you are still posting in the beginning forums, you shouldnt be worrying about it, lol

But hey i guess if u wannapractice, have at it.
#3
sweep picking is a way of playing arpeggios w/o picking every note...you're essentially "sweeping" or "raking" the strings with the pick. there's a pick n' grin video on sweeping here on UG and its quite good, i'd suggest you check it out.