this is a lip-sync tutorial i made on mamshmam.com:
MOUTH SHAPES
to start doing lip sync you will need replacement mouths, this method was developed by aardman after the wrong trousers so each animator would have the same style of lip- syncing and so that they wouldn't have to resculpt the mouth every frame. It is a very quick and easy process to animate, but it is really annoying to sculpt all the mouths. you will generally need about 12 mouths, and if you need 2 seperate sets for frowning and smiling, but this is usually not needed. These are all the mouth shapes you will need 
you do not have to make these out of clay, some people use paper, you could even just print this picture off and stick it on your characters mouth. But clay generally looks more realistic as it is the same texture as the face. Now before you make these you need to decide what type of replacement mouth you will use, you can either use Stick on, which are the 2d replacement mouths i used in my lip-sync video or full replacement mouths, which is when you cut out the whole lower jaw of your puppet and make a 3d replacement for each mouth shape like in this picture 
this method is alot harder, but looks SO much more proffesional anyway, moving on. Once you have made them, you need software.
SOFTWARE there are many good programs to help you with lip sync, the one i recommend is papagayo once downloaded it comes with tutorials, and audio files for you to practice your lip syncing. Basically how it works is that you load your audio file into it (the file that you are lip syncing to), Set the frame rate and then you type in what the person is saying in the little box. It will detect the mouth shapes you need, you then have to arrange the timing of the words, sentences and syllables in the sound wave above. When they are arranged press play. The mouths on the right should be synced to the audio. you can tell what mouth shapes you need at what frame by skipping through the papagayo file frame-by-frame (Each line going down represents a frame). you might want to write this down somewhere so you can look at it while animating. Other good programs for this are Magpie and Jlipsync Expression
Now, once you have what mouth shape you want on what frame, you can't just make your character sit there and only move its mouth. You need to give it expression, like actors do. They don't just stand up and talk, because that would be crappy acting, they use expressions and move around. in claymation moving around could be a problem, as your character could be hard to move. E.G a blob. But, to quote from the special features on the chicken run dvd "1/2 of the acting...... NO! 80% of the acting in claymation comes from above the nose." This means eyebrows are essential for lip syncing if you want it to be any good at all. Eyebrows can show so many moods, so many in fact that it would probably take hours to list all of them, so i'm just gna list some Raised eyebrows: Happy, surprised, sad, begging, amazement etc. Lowered eyebrows: Angry, confused, confident, determined etc. so yeah, i could have gone on for ages there, but i didn't so i'm just Going to say MAKE EYEBROWS!!!!! thankyou.... Credits: Google images Stop-motion-magic Stop mo works my brain and Aardman, for the quotes and for just being generally awesome
