Sweep picking is playing (basically) a chord, except you play one note after the other, and you release each note so that you actually play a lick.
The actual technique is in your right hand, you make only one motion, and you can play up to 6 notes.
But go and check out a guitar teacher, so that you can get rid of your bad habits. (I might be wrong, someone just told me Petrucci played better than me... :( )