In reply to heallan:
Dusty sport routes on dodgy rockpiles available within Lima and a mix of dusty trad and sport up at Canchacalla about 90 mins from the capital.
If you speak any Spanish get down to Basecamp climbing wall in Miraflores, Lima. Pound on the door till someone opens it as they keep it closed now even when they are open because their business license is as a "members club". Once you are in you can climb. It is 15 soles for non-members and there is usually a good vibe on a Friday night with bouldering, tunes and drinking! Manolo or one of the guys can give you advice on areas to climb.
However, the best website for finding info has already been posted - toposperu. As far as I know there are no rockclimbing guidebooks to Peru.
Hatun Machay is a good set up for sports climbing and there is plenty of rock to go at there. Huaraz is your best bet for finding bouldering, sport, trad, big wall, alpine/andean!
Huayllay in Cerro de Pasco is supposed to be excellent rock climbing. Think the weather for climbing is July/August.