Supposed the various kinds can help with removing toxins, muscle aches and more.
These are some sites I liked when looking for info on sea salts/bath salts.

http://www.saltworks.us/salt_info/bath-salt-guide.asp
http://www.saltworks.us/salt_info/si...itsOfBokek.asp
http://www.sfbsc.com/shop-bath-salts