Looking to improve my wired/wirelss home network setup...?

I have a handful of devices that are connected to my home network, some are wireless, and some are hard wired. I'll start off by listing my devices, location, and connection:

- Laptop (wireless / 5 feet from the router)

- PC (hard wired / in basement, approx 20 feet from router)

- XBOX 360 (hard wired / 12 feet from router)

- Garage PC (wireless / approx. 50 feet from router)

(Connected through access point in basement)

I am currently using a Linksys WRT54GS V.6 router. I also have a wireless access point that I have placed in my basement, so I can connect my garage PC to the network.

.My devices are not all running at the same time, at the max, 2 of them would be. I do have the garage PC connected through the Access Point, that is located in teh basement.

Not sure if I have this set up correct. I tend to lose internet connection when usingg the garage PC and Laptop at the same time.

I am connected to Verizon DSL, but that should not matter.

Any help is appreciated, suggestions are highly welcome too.