Remote desktop instructions

hate the be the 'hold my hand and walk me through it' guy, but i just cant get it to work.

so, i'm asking for help setting up a remote desktop system for 3 or 4 computers...

my questions are:

1. do all systems need to be set up the same way? or can i set all computers to 'allow' and have one master computer to view from?
2. do all systems need to be the same version of windows? i think i'm running two versions of xp and two versions of vista...

i guess i'll start there.

i have a wireless internet connection, but my pcs will be tethered via ethernet. right now i'm just trying to get my vista laptop to connect to my pc.
if you could start me or point me in a direction...

ps.
i tried the tutorials online to no avail...?

To my knowledge, all Windows PCs have the "client" remote desktop, but only the Pro/Business/Ultimate versions have the "server" part.

XP Home can connect to XP Pro but not the other way. Use the free version of LogMeIn.

Well basically, for any windows OS, you need to have a business version like xp pro, vista business/ultimate in order to be able to "serve" meaning allowing other people to connect. If you have xp home edition or media center then you cannot serve, nobody will be able to connect to you, but xp pro can. In other terms, all versions have client but business versions have server. However there are so many freewares on the net that allow you to do just that like VNC viewer.