HTML & CSS
As a relative beginner in web development, I’ve found Jeffrey Way’s 30 Days to Learn HTML & CSS to be really useful.
He takes you all the way from a Photoshop template to an active website. He makes use of Sublime Text 2 – a fantastic text editor with an unlimited trail period – and even covers two supremely useful topics: Snippets and Zen Coding.
I’d like to recommend two sites that I’m currently using, the first is Code Academy’s Code Year, which takes an incremental approach and offers practical examples and a useful Q&A forum.