Knowledge

Knowledge may be one of the easier things to share: It obviously doesn't get less if it is shared; it needs sharing.

General

 * Free content
 * Free software


 * Literature
 * Books

Skills/ Manufacturing

 * tsolife.org - Travelling School of Life, a skill sharing network
 * Instructables - website devoted to sharing knowledge on how to construct things
 * wikiHow - a wiki designated to share knowledge on how to do things.