Wireless print servers, depending in your router, can be hooked via ethernet directly into the router or wil register with the router as a wireless device. In either case the path is laptop, router, print server.
3rd option is to link wirelessly from laptop to print server. IE: the functionality does not require the router being persent.
I have used this one with good results and it's fairly cheap.
http://www.dlink.com/products/?sec=0&pid=38
There is also this one for a couple bucks more that does G
http://www.dlink.com/products/?sec=0&pid=313
Check the specs on your current router.
A lot of times your netwrok will fall back to the slowest device on it.
So if the router is B adding anything faster like G or N will not be a benefit as the faster devices throttle back.