A long and reliable list of 26 English suffixes is available at About.com. Suffixes are organized by which type of word they modify and include the general meaning of the suffix and an example of a word that uses that suffix.
Going beyond a simple list, About.com also offers advice for recognizing and applying new suffixes. The site provides tips for building a bigger vocabulary by adding suffixes to existing words and how to use suffixes to turn one part of speech into another, such as a noun into an adjective. About.com also includes rules for spelling changes that may occur when adding a suffix as well as general situations where adding suffixes is not grammatically correct.