WSGI is Python's answer to Java's servlets, just not as "enterprisey". I've been doing some tinkering developing a WSGI web app, but was highly confused about which servers support WSGI conformant apps and how they did so. Uche Ogbuji's introduction to WSGI is quite good, especially about the underlying design principles, but doesn't quite connect the deployment dots.
I found Jason Briggs "Getting Started with WSGI" to be a nice complement as a slightly more basic introduction. And it touches a little on the webservers that support WSGI.