This is a quite old thread, but as the question remains relevant, please forgive the following plug. We are in the process of writing an introductory book on (some aspects of) equilibrium statistical mechanics, with mathematicians (and mathematically-inclined physicists) in mind. Early drafts of some chapters can already be downloaded from this page. More should be available soon (as soon as we consider them presentable).

This is a quite old thread, but as the question remains relevant, please forgive the following plug.

We have finished writing an introductory book on (some aspects of) equilibrium statistical mechanics, with mathematicians (and mathematically-inclined physicists) in mind. A draft of the version of the complete book, as it was sent to its publisher (Cambridge University Press), can be downloaded from this page. It should more or less coincide with the final version (modulo corrections that will be made on the galley proofs), that we hope will be published mid-2017.