Well it's like skateboarding but with a longer board. Obviously the potential to fall is more than just there... it's hardly less than a guarantee. That's why you wear lots of padding and armor when you go.
I've never done it but I'm not really even good at skateboarding. I'd like to think that learning that would be important to do before trying mountainboarding.
I would also say get Body Armor w/spine protector (Pressure Suit) Gloves, and a closed face helmet.
****You don't want an open face helmet as for your feet are in bindings and you will fall on your face or back/ass.****
I also recomend Impact shorts too! You can find those in snowboarding gear.
All of the above mentioned gear can also be purchased on eBay as well. I get killer deals there.
A total Mountian Boarding setup will run you around 500.00 or more.
My board ran me 600.00 alone. My armor ran me around 300.00 for it all ( helmet, pressure suit, gloves and Impact shorts)
But once you buy the gear that's it no more cost.
Except for the occasional trip to the hospital. LOL
BTW Andrew I recomend the ski slopes in the summer to board on, and also try out the enchanted forest too.