The Lake Charles Power Squadron gives the course and test for free. They just as for a $5 donation for food and drinks they serve for lunch. I think they do the courses 4 or 5 times a year. They are located by the I-210 launch.
The next one is Oct. 3rd, 2009. You can register at Ship to Shore. They teach everything you need to know, then give the test at the end of the day.
http://www.lcpsonline.org/view.asp?id=2