Shared Documents - desktop (Windows 7) laptop (XPPro)

Hi, I have a desktop with Windows 7 and a laptop (XPPro) - I travelled with laptop and added a considerable amount of information to many files (mainly OneNote and Word). I have a shared document folder and shared information without any problem with a friend whom I stayed with. Previously, I have copies whatever files and manually transferred them to desktop (yes I know not the way to go) but now I would like to set up a shared document folder in desktop and connect with "Shared Documents" on laptop. Had a heck of a job even finding "shared folder" Windows 7 - eventually "Computer/Public/Public Documents" - ok so far but how do I connect the two folders? (laptop/Shared Documents with desktop/Computer/Public/Public Documents) - thanks - please explain to someone who is not computer savvy.

Hi,
Have you set up all permissions on both PC's.
On the Win 7 PC type Sharing in the Search Box.
Choose Manage advanced sharing settings.
How To Geek has some suggestions on sharing between Win 7 and XP.

I made a tutorial a really long time ago for this:
Share files over a network

You can't "join" two folders, but you access one same folder on both computers. The tut should explain pretty well.