Ill write a Tutorial for Pokemon Emerald, wait for update.....
[Edit]
To begin you need the VBAlink 1.7.2 or any version of
VBAlink...NOT VBA...There is a difference in the two VBAlink allows the ability to link games while VBA does not.
In VBAlink, before starting any game goto Options>Link
a window should pop up...
If you are going to run it on the same computer than choose
One Computer
If you are going to Do a Local Area Network than Choose Lan and make one person start the VBAserver!!
Type the amount of people that will be playing
[img width=400 height=166]http://www.geocities.com/shojixvaj/lanamount.jpg[/img]
Than you should type the IP in the SERVER IP ADDRESS of the LINK OPTION in the VBAlink
Click Connect and Wait. Something should popo up and say either it worked or YOU FAILED!
But that is all there is to it, for anygame...Once it connects, run the Game you wish to play multiplayers...