there is many ways to do this. I can explain to you how pcAnywhere works and remote desktop.
pcAnywhere and remote desktop share the same features: they have a instant messenger type chat feature, they let you remotely control keyboard and mouse functions, you can see what is on the computer that you are controlling as if you were there.
pcAnywhere is more secure, has much more features, and unlike remote desktop you can do file tranfers between both computers. to set them up takes basic networking knowledge so spdf you will have a steep learning curve. VNC, i beleive requires more effort than pcanywhere or remote desktop to set up.
windows has remote desktop features. you can use remote desktop on non-windows XP computers by doing this:
To install Remote Desktop Connection (32-bit computers)
On the computer running Windows 95, Windows 98, Windows NT 4.0 or Windows 2000, insert the Windows XP Professional compact disc into your CD-ROM drive.
When the Welcome page appears, click Perform additional tasks, and then click Set up Remote Desktop Connection.
Follow the directions that appear on your screen.
if you need help setting up remote desktop or pcAnywhere I can help