Here's some suggestions on the license under which the joint Wiki approach to the howtos could be published ... the first two differ in whether the conents may be used commercially ...

- http://creativecommons.org/licenses/by/2.5/
- http://creativecommons.org/licenses/by-nc/2.5/
- http://www.gnu.org/licenses/fdl.html

One of these (or some other one? Open for suggestions ...) should be the "default" license unless otherwise noted by the respective author ...