Occasionally I run across sites or other sources that offer content useful to me as a game maker. I’ll list them here.
(Anything that might be helpful to the study or practice of level design that isn’t an article.)
Speed Runs dot Net
Might be down — not looking good at the time of this posting.
Free 3D Assets
(These sites all provide primarily “free” 3D assets. I use the non-air quotes there to indicate that while most of the assets are free to download, I’m a little wary of the origin of some of the content and I doubt these sites are checking each asset to make sure they have the right to distribute it. If the origin of an asset is in question, always make an effort to see that you really have the right to use it. I HAVE NOT used all of these sites.)
3D Models & Textures
Unity 3D Assets & Scripts
(they have a variety of assets for other platforms as well)