XP Pro: How do I connect two pc's to each other through a Router?

[Steady Teddy]

I have cable modem with two pc's, one old and one new, both running XP Pro and a Linksys BEFSR41 router.
I would like to access files from my old pc to my new one through my router but I'm confused at how to go about it. All I know so far is if I want to access my old pc through my new pc via the router, I have to establish a "Workgroup" and give each pc it's own identity. The directions given in the XP "search & help" are somewhat vague and confusing.
I tried setting up a "home or small office network" with the Network Setup Wizard but I chose the wrong settings and lost my internet connection. I had to go back to my restore point to get my original settings back.
Is there a web sight that provides clear step by step instructions on how to configure both pc's so I can access files/programs of one from the other??
Both pc's have an internet connection and Linksys tech support told me that they cannot help me further because they don't offer support for what I'm trying to do. They said as long as both pc's have an internet connection then the router is working correctly so it's my problem.
The only info I've found is how to connect two pc's to a router but not how to connect two pc's to each other through a router.
Can anyone help or at least steer me in the right direction?

Thanks in advance

[Confused]

They have to be in same workgroup which they probably already are. Then you have to give permission to each file, HD, printer that you want to share. For instance, go to my computer, select your HD, right click and select properties. One of the tabs should be for sharing.

For printer that is hooked to one PC, it also has to be installed on the other and again right cliuck and select properties and enable file and print sharing.
Chas

[reboot]

Run the network setup wizard, create the floppy, take it to the other computer, run it.
Open Explorer, right click each folder you want to share, select "Sharing and security", share what you want.
Done.

[Steady Teddy]

O.K. thanks guys. I just ran the Network Wizard for my main pc. Before I run the Wizard for my secondary pc, I have to ask:
Now whenever I try connecting online, the "Work Offline" window pops up telling me "No connection to the internet is currently is available. To view internet content that has been saved on your computer, click Work Offline."
Of course I can click either option and connect anyway but how do I get rid of this annoying window??

Also, do I need to have my main pc on when I'm running the Wizard on my other pc?

Thanks again