For synthesis my recommendation is "Controlled and Living Polymerizations: From Mechanisms to Applications" edited by Krzysztof Matyjaszewski and Axel H. E. Müller unless you are looking for something really general and introductory.
There is a number of good books, see above. I can add, for instance Anionic Polymerization by Quirk and Fetters. It strongly depends on the monomers you plan to use and products you need.