As it was mentioned above, first and most important is to find a vet that is good at it.
Our Zeus had his cropped at 8 wks old I believe and 4 weeks later his ears were ready and looking good!
1st week - ears stitched up, kind of bloody and scabbing. He wanted to scratch them alot so we bought booties to put on his feet when we weren't able to watch his every step. Ears tapped up to a small cup resting on his head (upside down).
2nd week - stitches removed but ears still kind of scabby. Cup still on his head.
3rd week = most scabs are gone, cup removed and replaced with two sticks tapped to his ears connected in the middle.
4th week - scabs are gone, everything healed up, ears retapped with the two sticks.
5th week - After 4th week and only 2 tappings, his ears are standing up beautifully!
We got lucky with Zeus since most dogs take longer, even 3 months before their ears stand. However, I would say plan on having the little one away from the puppy for AT LEAST 2 weeks.
Hope this helps and if you want to see some pics of Zeus with his ears, I have pictures from almost each week when he had his ears done on my website.
http://myboxer.freehosting.net