For steel beams, these are relatively simple.
A simply supported beam requires two different supports: one to withstand vertical and horizontal forces (pinned support) and one to withstand only vertical forces (roller support).
Here are examples of each (click the links to see more examples and different types):
http://web.mit.edu/4.441/1_lectures/1_lecture13/pinned_1.gif
(source: mit.edu)
http://ceephotos.karcor.com/wordpress/wp-content/uploads/20110923-kjans-Bridge-Roller-Support-Manistee-MI.jpg
(source: karcor.com)