Multiple devices -wireless network

When connecting many devices to a wireless router your issue is not going to be whether all the devices can connect, but more likely whether the router can handle all the traffic...
You could connect 10 devices easily to any wireless G (54Mbps) router but if they all connect at the same time and the traffic increases your speed will probably drop significantly.
I would suggest atleast a 300N router with MIMO, possibly a dual band router.
No need to spend a load of cash, there are decent priced MIMO routers available on the market.