Survey on #P and/or counting problems
L. Fortnow. Counting complexity. In L. Hemaspaandra and A. Selman, editors, Complexity Theory Retrospective II, pages 81-107. Springer, 1997

This gives more of the structural complexity point of view (complexity classes, oracles, etc.), and discusses other classes related to #P. Although it's from almost 15 years ago, it's really not that out of date in terms of results.