Option 1: You can share the printer that attached to the desktop, but this means the desktop has to be switched on in order for the laptop to see the printer. Below is one of probably many guides to this found by googling
http://www.microsoft.com/windowsxp/u...utt_july2.mspx
Option 2: can your printer connect via ethernet to your router? (mine does) this avoids the need for either a print server or having the desktop pc switched on.