If the folders and printer that you want to share are in the XP PC, having Vista in the Laptop shouldn't make it any more complicated. Make sure that the folders you want to have available to the Vista Laptop have been "shared" by right clicking and selecting the Sharing & Security option. Similarly, "share" the Printer.
Make sure that any firewall software running in the XP PC has been configured to allow access to the Laptop. Also, both computers should be in the same Workgroup.
Have a look at my posting click here for details of setting up a "Network Printer" in Vista.