This is the IBM i Community pages from IBM. You will find blog posts, articles, and discussion forums.
PowerWire published IBM i, AIX, and Linux news on its web site. You can also subscribe to their monthly newsletter.
Scott Forstie, Db2 for i Business Architect, has a gists page where he publishes useful SQL examples.
The IBM i Reference Pages community web site is filled with useful references.
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.