Stomp pads are gripy pads that are stuck on the top of a snowboard just in front of the back binding. There are many types of them from rubber pads, to spikey blocks, and individually placed spikes (the type shown here). They are a very handy invention that helps your back foot grip the board better when you only have your front foot in the bindings.
Snowboarding has many situations where you only have your front foot in the bindings with your back foot resting on the top of the board, like getting on and off of chair lifts, riding drag lifts, or when skating the board across flat areas. It is good to be as comfortable and controlled in these situations as possible, which is what the stomp pad is for. Without a stomp pad the back foot can slide across the board easily, loosing your control and balance. The stomp pad simply gives your foot more grip so you can keep your balance and push on the edges better.
Stomp pads are also pretty handy for knocking the snow off of the bottom of you snowboard boots before putting them into the bindings.
On to the Protective Clothing section.