This site teaches the differences between simplified and traditional characters and provides a complete list of simplified characters and character components.
It includes 14 productive components and 134 productive characters, which can combine with other components or characters to form new characters, and 350 simplified characters and 39 variant characters that cannot be used to form new characters.
It's an old-style site that uses graphics instead of text, but the lists of characters and radicals can be found in text form here: http://www.skritter.com/vocab/list?list=302418553