In his latest newsletter (Issue #185) Pavel Tsatsouline recommends Coach Sommer's book "Building the Gymnastic Body"
Comrade, Building the Gymnastic Body stands out against the majority of bodyweight training books by its focus on strength. What makes it really unique is a wealth of unique exercises which develop exceptional tightness—the foundation of great strength. The range of progressions is broad enough to cover anyone, from a 98-pound weakling to a superman. Get Christopher Sommer's book.
He surely knows what he's talking about 8)