The following websites are good starting points (no particular order)
- https://sites.google.com/site/scriptsexamples/ -- by James Ferreira
- Pioneer in presenting GAS to the general public.
- Wrote a book about it: Google Script: Enterprise Application Essentials: Adding Functionality to Your Google Apps
- https://sites.google.com/site/appsscripttutorial/ -- by Waqar Ahmad
- Large amount of snippets, including advanced coding samples (see Doodle)
- http://mashe.hawksey.info/ -- by Martin Hawksey
- Master at data visualization on social media
- http://www.scoop.it/t/gas/ -- curated by Martin Hawksey
- You're able to suggest new articles on GAS on scoop.it
- http://ramblings.mcpher.com/Home/excelquirks/gooscript -- by Bruce McPherson
- Large collection of all kinds of programming stuff
- http://stackoverflow.com/questions/tagged/google-apps-script
- All GAS related question are found here.