Verified answer

no. once you sign up for your internet connection, you can use as many computers or devices you want on it.

I'll second what MadMax08 stated with the following exception. Some ISPs do have download/upload limits to make sure people aren't abusing the network (think of people doing large amounts of file sharing or a business using a home account). Connecting a console shouldn't transfer a huge amount of data except for some game content (i.e. new maps, game objects, etc...) or downloaded games. This should not be a problem unless you are also doing a large amount of file transfers on your other systems and the console pushes you over the limit. It isn't very likely to happen for most users.

No, it's sort of like having a router, but only for DS and Wii. It will not charge you anything. Hope this helps!!!