The raft is made in the same way you would create a trap-door with Wooden planks(6 wooden planks, creating a sideways door), but to make a raft you must use Bamboo. Sticks are not compatible with this recipe. The raft is used as a faster way to get across water, and therefore erasing need for a boat to be coded into the game. However you can not stack these and if you fall off it it is hard to get back onto it and if you mine will drop bamboos, so try to avoid that.
The Mine Blocks wiki is kept running with support from you! :)