Most Baptists are mission minded.
Southern Baptists support missions thru the Cooperative Program. That is we pool our resources and missionaries are sent out thur Home Missions (North American Missions) and Foreign Missions (International Missions). These missionaries are in essence employees of the SBC and thus are able to go right to the field that the Lord has led. (note: some SBC also support Independent missions as well)
Independent Baptist missionaries will go on deputation for many months if not years to seek partial support from each of several churches. There are dozens of Independent mission boards. Standards vary from board to board. If not mistaken, there may be some missionaries who do not even go under a board.
Some groups have "split" due to Doctrine issues ie Conservative Bap Association, GARBC, ect.
Some Baptists had separate groups due to language, though that is somewhat few and far between now.
There are specific doctrine groups, such as Seventh Day Baptist (worship on Sat), Free Will Baptists - (believe they can loose their salvation)
So hows this for a start?
Here is a good link: ALL ABOUT BAPTISTS