Here are some links to various media for those interested in learning more about latin dancing:
Here are some music videos of some of the various dances we do at Salsa and Latin Dance Club. This should help you get a feel for the differences in the music.
If you are looking to learn the steps to the basics, or just looking for a quick refresher, take a look at these videos. DISCLAIMER: They are missing a LOT of the style that makes these dances what they are. They are primarily so that if you haven't been to club before or if it has been a while and you want to remember the basics, you can get access to what you need to get yourself started.
Here are some videos of people dancing. These should give you some ideas for moves you can try, as well as give you a feel for the style/flexibility these dances have.
Check back later for Merengue videos!
Here are some channels with lots of really awesome videos. Take a look.