Animated Libraries at the University of Iowa
This site contains animated libraries of the phonetic sounds of Spanish and English. Available for each consonant and vowel is an animated articulatory diagram, a step-by-step description, and video-audio of the sound spoken in context. It is intended for students of phonetics, linguistics, and foreign language. There is also an interactive diagram of the articulatory anatomy.
This site is a general introduction to articulatory phonetics and acoustic phonetics. You can practice sounds and do exercises to check if you really learn these sound.
International Phonetic Association
The official website of IPA with useful quick links, history of IPA and updated information.
Sounds from Peter Ladefoged's books
All the material on this site is also available on the CD attached to A Course in Phonetics.