CTG.cz
A detailed map showing which trams operate in Prague by night and day.
http://www.ctg.cz/transport/pt_prague.html

DP-Praha
Click on the "Search for Links" section on this page to access an interactive Prague public transport route planner.
http://www.dp-praha.cz/en/index.htm

Prague2001.com
A map depicting bus and metro routes in the city.
http://www.prague2001.com/map2.htm

Prague - Subway
An easy-to-follow map of the Prague metro system.
http://www.czechsite.com/images/metro.jpg