Alisha, T1-11 is basically just a plywood made of pressure treated wood. Maintenance would be about the same as for a deck but cut the pressure way back if you power wash. Since the wood will be vertical instead of horizonal, it should get less dirty except what watering the lawn splashes on it. Check the post on decks for specific brand info and Steve:'s posts are usually pretty well on track for this at least for the southern states.
I still go with your friendly local paint store as the best friend and source you can have for your area, particularly Sherwin-Williams and Benjamin Moore dealers. They have a stake in helping you get the job done right--your future business and goodwill. Somebody local owns or runs that business and should not consider you just another pretty face.