Wireless Networking

http://www.microsoft.com/windowsxp/using/networking/default.mspx

How to troubleshoot home networking in Windows XP

Sharing a printer... In a nutshell
Here's part of what Smart Computing has to say about sharing printers:
To share a printer over a network, your network must be configured and working. If you haven’t set up your network, open the Start menu, select Help And Support, and select Networking And The Web...

For secure printer sharing, your host computer (the computer that has the printers attached to it, sometimes called the print server) should be running WinXP SP2 (Service Pack 2)...

Although the host computer should be using WinXP SP2, the other computers on your network can operate with Windows 98/Me/XP using the methods discussed here...

I imagine that you can replace WinXP SP2 with Vista. Perhaps with some adjustments. :-)

Smart Computing also has a nice article about file sharing.

Here's part of another take on sharing a printer:
Share your printer

Sit down at the computer that your printer is physically connected to, press the Start button, and go to the Control Panel.
1. Double-click on the Printers and Faxes icon, and new window showing an icon for each of your printers will appear.
2. Right-click on the desired printer and click Sharing.
3. The Sharing window will open; click the radio button next to Share This Printer, and then type a name that you’ll remember into the Share Name box.
4. Click OK to close the window.

Install the printer on all other computers

You’ll need to install the shared printer on each computer that you wish to print from. To install the shared printer, click the Start button and go to the Control Panel.
1. Double-click on Printers and Faxes.
2. On the left-hand side of the window, click on Add A Printer.
3. Click the radio button next to A network printer… and hit the Next button.
4. Click on the Browse button.
5. Locate the name of the computer that your printer is physically connected to, click on it, and then highlight the name of your shared printer. Click Next and OK. Your shared printer will now be installed.