extending wireless with an access point

First off, let me say thank you for any help you can give. I really appreciate it.
That being said, let's go!
So I have an old D-Link (DWL-G810) accecss point hanging around and I decided I want to use it to recieve a signal from my bedroom so I can set up a home theater PC in the living room. The problem is that I can't seem to figure it out. Here are all my components and system specs:
Wireless router: Linksys WRT54G
Location: Bedroom
Access Point: D-Link DWL G810
Location: Living room
Switch for Access point (so I can add another computer if I like): EZXS55W
Location: Living room

I have a computer that is hard wired to the router and a computer that needs to be wired to the access point, we will call them PC1 and PC2 resoectively. Here are the specs for both:
PC1:
OS: Windows XP Professional SP2
Motherboard: Asus P5K SE
CPU: Intel Core 2 Q6600
Ram: 2 GB OCZ Platinum 1066
GPU: ATI Radeon HD 2600XT
Sound card: SOund Blaster Audigy ZS Platnium
PSU: Rosewill RP550-2

PC2:
This pc is currently unnder construction, but to set up the access point I am using an old Dell Inspiron 5100. The specs are here if you need them.
OS: Windows XP Professional SP2
Motherboard: (Unknown)
CPU: Intel Pentium 4
Ram: 256 Mb (unknown brand)
GPU: Mobility Radeon 7500
Sound card: Integrated (presumed)
PSU: Unknown

In any case, if there is anything that is left out that I can include, please let me know. I jsut need some step by step instruction. Even if it a link to a site that can show me how to do it or even just a push in the right direction. Thanks again for any help you can give me!

Regards!

 

Sounds like your trying to create a bridge or need a wirless distribution system. That WRT54G may be usefull, check out this link
http://www.dd-wrt.com/wiki/index.php/Tutorials
If that router is the correct version you can flash it with their firmware and use the dlink as the main AP & the WRT as the bridge client.