BUG
The site offers general guidance on hitching a ride from Prague, as well as hosting a database which lets you search for or offer a ride.
http://www.bugeurope.com/transport/hitchpra.html

Hitchhiker's Guide to the Czech Republic
As the title states. In Czech only.
http://sweb.cz/IvanStropek/eautostop1.html

The Hitchhiker’s Guide to the Czech Republic
One man's experience of hitchhiking in the Czech Republic. In PDF format.
http://www.zaitchik.com/clips/Zaitchik%20story.pdf