Some years ago when I was first trying to learn web programming, I discovered a resource called W3Schools. This one comes under the “I can’t believe it’s free” category. They have an amazing amount of material covering all aspects of client-side and server-side scripting. The site is cleanly-designed, very functional and features clear explanations with code, cut-paste examples and dynamic demos. I can’t recommend it enough.
I’m currently using it to learn the basics of AJAX. I know, I’m years behind the times, but I’m excited by the possibilities for dynamic bioinformatics websites. Type in a gene UID, get a bunch of data back from an NCBI XML file, that sort of thing.