Links:

AGS - Links to AGS related sites.

Adventure game studio - Home of the popular AGS.
Skimbleshanks - Resource site like this one, it's no longer being updated.
instagrounds - a site with pre made graphics.
agsuploads - A place to upload your finished game.
agswiki - Some info on AGS.
walkthrough wizard - Site full of walkthrough for AGS games.

Tutorials - Links to sites with tutorials
kafka's Koffee - A good site with some good animation tutorials.

Sounds - Links to sites where you can get free sounds.
findsounds - Site with loads of sounds.
creativecommons - Some different sounds on this site.
freesound - Another site with a load of sounds.
3dmmstudio - Contains packs of sounds to download.
musicrobot - Contains midi versions of a lot of songs.

Misc - Links that don't fit in the other sections.
herculeaneffort - Home of the hugely popular Apprentice games.
The Inventory - Free internet magazine for adventure games.
Galbadia hotel - Site with MP3's from hundreds of games.