Non-Language Specific Development
- StackExchange: Software Engineering.
- Like StackOverflow but for concepts, methodologies, etc. as opposed to specific code issues.
- WikiWikiWeb.
- The Wiki ever (yup), famous, quite basic visually, but lots of good information.
Web Development
- Spellbook of Modern Web Dev (6/2019).
- Fairly extensive guide to resources on modern web dev, unfortunately it is quickly aging.