There are a couple different type of sweeps, each somewhat schematically different from the other.
Rocket Sweep (used by the flexbone guys - think Georgia Tech)
Toss Sweep
Jet Sweep
Stretch - Starting with the non-"sweep" play. Stretch is basically outside zone, although some teams vary the aiming point for the running back (to account for usage of a TE). Each of the lineman are going to take a significant lateral step, moving in concert to the play side. Their goal is not vertical movement like in the inside zone; rather, they want to get the DL and 2nd level defenders running laterally. The variation in speed of the defenders combined with the leverage of the offensive lineman will dictate where the play will hit. In a perfect world the EMLOS would reach the defensive contain player, allowing the RB to turn the corner (much like he would try to do on a sweep play). But, again highlighting the leverage and horizontal movement of the OL, if an OL is unable to reach a defender because he is pushing so hard to get outside, he can flip his hips, drive his man to (and through?) the sideline, thus opening a gap for the RB to cut inside the block and then bounce it back outside.
Rocket sweep - I mentioned think GT. They have the guy in motion every play...he gets to the B back in that offense and then goes laterally at pace. QB snaps the ball and flings it out to him and he catches at or beyond the tackle position. Block no interior lineman playside...everybody reaches/rips through to 2nd level.
Toss sweep - I remember one of these to Shonn Greene in 2008. Not sure if we've run one since or not. Olddude actually hit on it pretty good. A lot of teams will tag "Crack" on this type of sweep, telling an outside receiver to crack down on a DL/LB in order to help free the edge. Usually what will happen on toss is there will be a down block by a TE, wing, or even an OT in some defensive fronts, allowing interior lineman (usually both guards, or maybe a guard and center) to pull out and lead the sweep. FB is responsible for either a kickout block or sealing the inside, depending on the team/play call. Guards are usually pulling for first color (hit the first thing they see), but if there is no fullback, the first puller will be the kickout (or "log" man if the defender attempts to wrong shoulder the play in order to spill it to the sideline) man and the 2nd man is the true "lead blocker".
Jet sweep - Extremely quick hitting play that involves a motion man coming at close to full speed towards the QB when the ball is snapped. Usually the QB will snap it when the motion man is at the outside leg of the guard to increase the "quick-hittedness" of the play. If there is a 1 technique to the play side, most times he won't even be blocked by the PSG...he will immediately move to the 2nd level. There is no pulling on this play as that would foul up the timing. OT and TE, if there is one, will reach the players over them and the running backs will, in most cases, carry out a fake indicating an inside running play (which is why it marries up so nicely with inside zone). Motion man, after receiving the handoff, bows back a little bit to allow for the blocks to take effect and eliminate threat of any penetration, then will turn the corner, cut inside or outside the WR block depending on leverage/play call and then try to get outside as soon as possible to maximize the distance the LB's have to travel to make the tackle. Ideally you force the safety to make this tackle, which means that you've at least gained a handful of yardage.