The Gospel Coalition posted an helpful article asking 20 church leaders what three books every church planter should read. (TGC Asks: 3 Books Every Church Planter Should Read)
I thought it would be helpful to see it in a list format with links. So, I put together this basic pdf document summarizing all of the recommended books. The 4 books that were mentioned by more than one pastor are highlighted. Of course, I would encourage you to look at the article and hear each man explain why he felt a particular book would he helpful.