Obviously the web is a phenomenal resource for learning. There are several websites that are especially good. First, please do visit me at the link below and don’t hesitate to ask questions.
Dommermuth.com: http://dommermuth.com/html5-playground/
Otherwise, the following are excellent resources:
Fonts
These two sites offer free fonts that you include in your work. DoubleClick does not factor the file size of the fonts you choose from either site into the max file size of your banner. These two sites are widely used in other front-end development as well.
Google Fonts: https://www.google.com/fonts
Adobe Edge Fonts: https://edgewebfonts.adobe.com/
General Questions
I find StackOverflow invaluable for general questions. Though the community can be harsh to newbs, it’s still an excellent resource.
StackOverflow: http://stackoverflow.com
HTML+CSS
CSS-Tricks: https://css-tricks.com/
Mozilla: https://developer.mozilla.org/en-US/docs/Web
JavaScript
GreenSock (GSAP): https://greensock.com
Mozilla: https://developer.mozilla.org/en-US/docs/Web/JavaScript
Miscellaneous
TinyPng is an online service that compresses pngs and jpgs. I particularly like it for shrinking down pngs.
Tinypng: https://tinypng.com/
Testing
Litmus is an online service that shows you how a huge variety of devices and browsers ‘see’ your work. I wouldn’t completely rely on it, but it is a good supplement to your testing.
Litmus: https://litmus.com/