You either want a introductory book in evolutionary biology or a book that offers mathematical models of evolutionary processes.
In my first class of evolutionary biology I had this textbook: Futuyama, Evolution I think it gives a good start to the field and offers a good overview of the difference subfields.
If you think you already know enough about the concepts selection, genetic drift, molecular evolution, etc… and you want a book that provides mathematical formulations of evolution, then you might want to have a look into the field of population genetics. On this post you'll find some book-recommendations
If you are particularly interested into molecular evolution, I'd suggest: Yang, Computational molecular evolution
Maybe you are particularly interested into the statistical methodology used in DNA annotation or in phylogeny. Then…. I don't know! It's not quite my field!
