Best way to start web development?

I've only ever done software development. What is the best place to start? I have a domain and hosting, but I guess I just don't know where to start.

I would like to create a sort of personal portfolio/workspace for myself. I want to be able to create a header document and then just include or import or whatever into every other page and things like that. Should I use a web framework for this such as code igniter or CakePHP? Is ruby on rails a better choice for a software dev?