If you do decide to go with Python, web.py (http://webpy.org/) is simple and you'll be up and running fast.
If you're interested in how it all works, dig into WSGI. And if you find that web.py is too low level, transition to Django after you have a feel for how web apps work.
Unfortunately webpy is poorly documented. Not good for a beginner. It is better for those people that know python well, and like to have absolute control of what's going on, and don't like the overhead of a large framework.
While webpy is small, I found myself often looking at the code, which has little commenting, to understand what's going on, or how to use a certain feature, mainly b/c the documentation is so lacking.
Indeed, but horizontal scaling has been common before Rails and will be common after Rails, since most web apps are stateless and transaction based. So, even though Apache and mod_blah only runs as one process, you can still horizontally scale. With rails it is apparently common to have more than one process per server.
It's not imaginary, but it is unimportant. Spend a day in #haskell, #python, or #ruby asking basic questions about the language, then repeat in #lisp.
There are helpful people in the CL channel, but most newbie assistance ends with the veteran delivering a scolding. That doesn't consistently happen in other language channels, but perhaps it should.
