That list above leaves a lot to be desired, and honestly otis would of been better off not replying at all since he is just giving him incorrect information.
You do not need a helmet, but it is recommended. You do not need boots as they will be a part of your rental package. Feel free to bring a music device, but you surely do not need a bluetooth headset...
That being said, where are you going to be riding? The temp outside will play a role in what you need to bring to keep warm.
Here is a basic list of things you should be wearing for most days.
Head: Hat or helmet with sunglasses/goggles depending on the day.
Chest: Base layer (thermal or something close), Mid-layer (some kind of wool/fleece sweater, or your jackets inner liner), and an Outer Layer ( something waterproof)
Hands: Waterproof gloves with a liner if you want (don't forget hand warmers if it is going to be really cold)
Legs: Follow the same rules as the chest, but it more important that your pants are waterproof as you will be sitting and kneeling in the snow
Feet: A nice pair of socks can be bought for pretty cheap ($15 for a really nice pair) and you will thank yourself later
Don't forget other things that you might want while on the mountain like small bottle of water, chapstick, snacks etc.