I find it's not as luxurious as a "normal" manicure, as using lotions and potions would stop the shellac adhesion, I think. However, different places do diffferent things - I had one in NYC last week where I had the cream and a small hand massage after the application.
There are 4 coats: all are applied as normal, but instead of allowing to dry, each coat is cured under a UV lamp, and is dry instantly. There are no risks to smudging or chipping.
I always have it done on short nails, so no problems there - it's just like a normal nail varnish. You can choose whatever colour they've got (or colours - my technician has all sorts on interesting powders that make for different colours or effects).
Once it's done, it should last for 2-3 weeks. Chipping highly unlikely, biggest issue is usually regrowth instead. Taking it off is a PITA: soaking pads in acetone, covering your nails with pads, wrapping in foil then waiting 10-15 mins. Much easier to have it done professionally, although I do it myself at home sometimes too (DON'T peel it off - it'll wreck your nails).
Using solar oil/good cuticle oil while it's on will help keep your nails fed.