The bigest problem i have found with XP is having the software firewall enabled. Open the network panel and verify in the advanced pane that it is turned off. I think the default setting for XP is to have the firewall enabled.

You also have to set up each computer to have an unique network address (the i/p address). Sometimes a DSL, a cable modem, or even an airport hub can act as a DHCP server and set the i/p for you. Sometimes you have to set them up manually yourself. To set one up manually you usually just pick a number unique to each machine.

Then select a folder to share. When it is running a small hand is displayed under the icon of the folder you are sharring.

Then just use to jag to connect to the XP computer in the finder. (go menu)

If this drive is one you use a lot , drag the icon into the menu bar of an open finder window. Then to reconnect you just click the icon. For some reason you can't seem to make an alias and put it on the desktop.