If you have configured IP, my above procedure should work. I never needed sharing when I had XP so have no idea about it but if you turn password protected sharing OFF in Windows 7 and enable File Sharing, you should be able to view the files shared in Windows XP's My Network Places (?); Share the files using Sharing tab by accessing the properties of the folder in which the files lie or the destination you need to copy the files to (not applicable for Drives). Select Share, add 'everyone' from Drop Down menu and give Read/Write permission.
Go to My Network Places and access the shared folder, copy the files from it or copy your files to it, depending on what you want to do. (Might need several refreshes for the Windows 7 device to appear in the network).
Also, remove the 'Everyone"'s read/write permission once you are done.
As for the easier way:
Install IP messenger on both machines, drag the files to msg window and select the user you want to send it. You'll get a notification on the destination machine, open it and select to save the files. Get them all in a folder before sending and send the entire folder for hassle free transfer.
