I prefer Python to Ruby, but language choice is another topic entirely. There are a number of web frameworks for Python that are AT LEAST as useful as Rails, including Django and Pylons. In some ways, I think Django might be better for the type of site you seem to be interested in. Of course, I'm going mostly on assumptions...

I know there are a number of Python tutorials that were written specifically for scientists that are new to programming. I would think that a few tutorials that use practical examples from your own field would make the wall a bit easier to scale than a tutorial that just addresses complete noobs? I don't know of any similar "Programming for Scientists"-type tutorials for Ruby... (?)

There is also a good intro to programming book that uses Python (Zelle is the author) that was recently adopted by MIT. If you want a stronger foundation - but with a potentially slower payoff - you should look at htdp.org and SICP, both of which use Scheme.