Are you wanting to learn how to guide or are you looking to learn how to row for your own private trips? If you're wanting the latter, I would skip the guide school and go for 4CWW's Private Boaters Course
. Its much focused on rowing and skills that private boaters need. They haven't scheduled the 2015 class, so you might give them a call to see if they could do one in June.
If you're looking to actually guide commercially, their guide school is also top notch and very intensive. They're one of the few companies that take their guide school on the Upper Animas, so if you want to experience some harder whitewater, 4CWW would be my choice.