I've posted this in another thread but: You can find Peet and Harwick's Theories of Development pdf online for free (just google it and it pops right up from a university website). The authors are admittedly Marxist but it does do a good job summarizing the existing theories of development and the history of development/political economy theory. The authors also add their critiques of each theory along the way. Its pretty comprehensive, but like I said it has a heavy Marxist influence so if you're not into that you might not like it. Although you could still just skip over the critiques and focus on the descriptions of the various theories which are quite well done imo.