Or how to code. Where you start depends on what you want to do with your skill.
For basic websites, here's a good guide for beginners learning html (the content) and css (the appearance). After you read the first page of the guide, hop on over to the website of the creator Shay Howe and go through his slides on the same subject. I thought the slides made the concepts easier to grasp. Or am I just too used to PowerPoint? Plus, I think some visuals on how code relates to output (I'm thinking literally a picture and arrows pointing from code to parts of the picture) would really help, too.
As you get more advanced, more resources for you:
1. JS Fiddle
2. Ruby Monk
For overall programming resources or how to program/code, there are a number of online courses and programs, like Treehouse.
What would you build if you could program? What are you building?