Well, how everyone said, there is not yet a didactic book for the entire subject but, there exists some texts and books about topics of the theory such that you can read rapidly than Ruelle.

Some examples:(all are rigorous)

The classical: *Gibbs Measures and Phase Transitions.*
De Gruyter Studies in Mathematics Vol. 9. Berlin: de Gruyter 1988. by H.-O. Georgii

*Entropy, Large Deviations and Statistical Mechanics.* Springer-Verlag. by Richard S. Ellis.

*The statistical mechanics of lattice gases*, volume 1
by Barry Simon 

And, there are many surveys and currently appears new reviews about some topics, some examples(I included pages of mathematicians that work on the subject, in their pages you can get some introductory texts):

http://arxiv.org/abs/0712.1171