In reply to Karabiner Karen:
I am not an expert, and prob repeating what many others have said, but this is what I know about lead climbing. If anyone more experienced than me wants to correct anything I said wrong feel free too.
Falling while leading above clip on a slab can be a bit dangerous as you scrape down the wall, this is one of the reasons you generally don't see many leading slabs indoors. On vertical slabs you ideally want to gently push yourself away if you fall off as you could potentially hit a hold on the way down. That said myself and plenty of other people have taken many falls on vertical indoor walls and never hit a hold or been injured. If you want to build up confidence falling off, it is safest on a gently overhanging to very steep wall, as you are falling into empty space and won't hit anything.
Try to avoid having the rope go behind your leg, as if you fall off you will be flipped upside down. You can also ask for your belayer to watch out for this and yell to you if they spot this. Also watch out for Z-clipping, where you take up rope to clip from under your previous quickdraw instead of from your harness, usually instantly noticeable by the huge amount of drag this produces.
Try to clip from good holds and a good position, don't be tempted when feeling pushed to try to clip from bad hold or from way below, as you will sap loads of energy pulling the rope up and you are introducing a huge amount of slack if you fall just before clipping. On steep ground I generally find it much better to climb until the next clip is very close to my waist, so I don't have to spend a lot of time hanging on one arm and can quickly clip.
I make sure I fall from above a clip at least every other climbing session to keep driving it into my head that falling from above gear is safe. Another thing to note, if you ask your belayer take you tight while above a clip then come off you will generally end up with an uncomfortable fall that swings you in quite quickly back into the wall. This is because a short pendulum swings quicker than a long one... basically unless there is risk of you hitting a ledge or a floor, a fall from above gear with a bit of slack out will generally be much more comfortable, though you will end up a bit further down the wall. For the first three clips the belayer should have minimal slack, be close to the wall and have a close eye on you. After that more relaxed belaying with more slack out is fine.