This link gives you a brief chronological listing of MSF activities since 1971. There is a basic charter to MSF that all members agree to uphold. The organisation relies heavily on trained medical professionals who are willing to donate their time and skills in order to bring medical aid to emergency and ongoing crisis situations. You can read more about volunteering with MSF here. This does not make you a member of the organisation but does provide you with periodic updates of MSF activities and information regarding MSF presence throughout the world.
Registration is open to all.
THE WWW MSF has a collection of national sites, offering information about MSF in a variety of languages.