A'llo I wouldn't really concern yourself with Steam just yet. I would focus more on getting a working prototype of your game sorted before looking into steam. I'm sure all the documentation you need for the Steam side of steam will be available on their website. As for VS side, you need to get some kind of steam wrapper thing from steam which will let you access / updates stats & achievements for your game via some Lua script functions...
But... as I already said: I wouldn't worry about it too much for now.