The basic DSL modem only provides one IP address to the inside of your house. If you buy a simple router for $29.00, it will take that IP address for itself. Then you can set the router up to provide IP addresses to all of the computers in your house using DHCP. You can then hook up as many PCs to the router as it has jacks for... usuall 4. Or, you can hook up a switch, hub or any combination of them cascaded to give you 250 jacks to hook up as many devices as the router can supply addresses for, usually 250 or so devices. If the router you buy also has wirelless capbility, all the better, as you won't have to hard wire anything.
You should have no problem hooking up a wireless access point inside of the router using either a jack on the back of the router or through a switch.
I was a Staples last year and picked up a wirless router with support for 250 devices, 4 hard wired ports and a PCMCIA wireless card for a laptop $29.00, so deals can be had.
My current home network consists of a DSL modem, a wireless router with 4 jacks on the back, and three PCs hard wired to it. The wireless router provides IP addresses to my three PCs and any wireless laptops/devices that come into my home. It works very well.
