I found this information and tons of really neat stuff (pictures, movies, etc.) at http://sohowww.nascom.nasa.gov/ , which is the homepage for NASA's SOHO (SOlar and Heliospheric Observatory) project. For a good intro, click on "Classroom" (on the left hand side, under the "RESOURCES" heading), and then on the section for "The Sun 101" course.
Answered by: Gregory Ogin, Physics Undergraduate Student, UST, St. Paul, MN
'Physicists like to think that all you have to do is say, these are the conditions, now what happens next?'
Richard Phillips Feynman