#Some things that I've found useful. My original plan was to write some tutorials of my own. I then discovered that I am not particularly good at writing tutorials. The new plan for this page is that I will link to some tutorials that I have personally found useful.
##Web Development: MDN -- Not a tutorial, but some of the highest quality web documentation around.
W3Schools -- Good-enough to excellent tutorials for most web related topics.
##Rust: Install Rust, and then use
$ rustup doc
The rust book, included with the install of rust, is an excellent tutorial. The included API reference is equally excellent, although not a tutorial.
##C: Beej's Guide to C Programming -- What it sounds like. Book length document covering the C language.
##Python: W3Schools Python Tutorial -- YMMV
##General/Other: Beej's Guide to Network Programming -- What it looks like. Examples are in C.
How to Ask Questions the Smart Way -- Also what it looks like. Read this before asking questions in forums/IRC/Mailing Lists/Matrix/Discord (gross)/Help Desks/Class/Reddit... You get the idea.