IBM i Community Pages
This is the IBM i Community pages from IBM. You will find blog posts, articles, and discussion forums.
PowerWire
PowerWire published IBM i, AIX, and Linux news on its web site. You can also subscribe to their monthly newsletter.
Forstie Gists
Scott Forstie, Db2 for i Business Architect, has a gists page where he publishes useful SQL examples.
IBM i Reference Pages
The IBM i Reference Pages community web site is filled with useful references.
Faq400
The FAQ400 site is in Italian and has a lot of useful articles posted on the blog page. Use a tool of choice to translate the site into your language of choice.