This page is dedicated to my favorite sites that are useful for web development.
MDN is one of my favorite resources when determining what the best web practices are, if a given css or javascript feature is currently supported by browsers or not. There are even tutorials on web development from the beginning!
W3Schools is another great resource for web development. They have tutorials on HTML, CSS, JavaScript, and more. They also have a try it yourself editor for each tutorial!
Stack Overflow is a great resource for when you are stuck on a coding problem. There are many developers who are willing to help you out!
Js fiddle is an outstanding resource to utilize, it allows you to create a mini webpage in the browser. This allows you to test out any CSS or JS ideas you might have on the fly!