Going to be editing this OP.
If you have any mapping-related problems, use this thread to ask them, rather than creating a whole new thread. This is not the place for requests. If you want to request a map to be found/made, create a new thread.
Do not post screenshots in this thread unless they are related to an error or question.
“Source Tutorials Source”
Compile Error Checker - Please use it to check your compile log for errors before asking any error-related questions!
Articles on Level Design
https://www.mapcore.org/articles/development/making-agency-the-popular-csgo-map-r62/ - The Making of cs_agency
http://www.farcry2.cz/czech_menu/ke_stazeni/mapy-download/Benova-bible-mapy.pdf - “Ben’s Small Bible of Realistic Multiplayer Level Design”
cgtextures.com - CGTexture’s Expansive Library of Free Textures
http://www.philipk.net/tutorials.html - Philip K’s Tutorials and Free Texture Packs for Source (see bottom of portfolio)
“The Official Facepunch Mapping WiP Thread v16” - Post your WIP work here.
http://leveldesigninspirationmachine.tumblr.com/ - “Level Design Inspiration Machine”