[mping]

I believe it's almost impossible to get away without knowing CSS/HTML and JavaScript/jQuery/whatever. SQL is a big plus, not essential but almost.

Im from a Java shop and recently started to learn rails, had a good experience with grails. The good thing about web frameworks is that you can reapply what you learn to other frameworks (ie, if you choose Django you can later apply some of the knowledge to Rails or whatever). My only nitpick with the whole ruby/rails stuff is that most of the stuff is mostly semi-broken in windows. Some gems need patching, others need native code (sometimes this code has to be compiled), others just don't work with gem X. I don't know how it is in the Python/Django universe, but comparing Rails to Grails (or any other Java/maven based project) I'm amazed at the low "respect" gem/plugin developers have for windows users. Java is really write once run anywhere, Rails just seems write once run in linux.

If you choose Rails, I would strongly suggest you to install a linux.