Wireless Network Hareware Confusion

Hey Everyone. I'm new to Major Geeks and definately a networking novice, and I'm confused by what hardware I need to buy to set up my wireless home network, so I'm going to write what I have and what I want to do, and I'm hoping someone out there can tell me what I need to do.

Have:
Desktop (upstairs) running XP sp1 hardwired into cable modem (I'd like to keep this computer hardwired in case something goes wrong with the network config)

Laptop running XP with wireless card (802.11g.. I think, but I can check on that... anyway, I know to make sure to match the frequency) that I use wirelessly at school daily.

Tivo and PS2 Downstairs

Want:

I want to be able to use my internet connection from downstairs on my laptop and for online PS2 gaming. For that, I'm pretty sure I just need to share an internet connection and a router would be just fine for that.

However, I'd also like to be able to use the Home Media Option on my Tivo and be able to access our home movies, pics, and music (located on the desktop upstairs) on the TV/stereo downstairs, be able to print on my upstairs printer from the downstairs laptop, and access files located on the upstairs computer from the laptop.

I think this requires something different from just sharing an internet connection, which as I understand it, is all a Router does.

As far as hooking up Tivo to a network, I'm good on that and have very detailed instructions

Gist of my Question:

Can one computer/device (like Tivo or a laptop) access other computers via a wireless router? or do I need something else? (I'm confused as to what a Bridge is and what an "Access Point" is.)

 

I figured out that I just need a wireless broadband router. Considered me schooled. On to the eithernet hardwiring problems for the one computer I want/need hardwired into the network.