I'm a mechanical engineer who taught myself to code and now I've written a full-blown web app. I'd recommend jumping right into Rails and building and breaking stuff, which is how I learned.

On the plus side:

-There's a TON of documentation, resources and help online.

-It's really fast to get started, so you'll get quick wins. This is key for motivation.

-It will slowly introduce MVC to you, but you don't have to build it yourself to get started.

On the minus side:

-There's a lot of 'magic' stuff going on, which can be confusing when you're used to explicit C code.