VATSIM.net is the main network site, it has divisions throughout the world. You need to join the network first then you can join the division closest to you where you would like to fly/control online (e.g. for me VATSIM-UK).

Go to http://www.vatsim.net and register there with your full name. It takes up to 2/3 days to complete the registration, so be patient. After you get your ID and password (both 6 digit numbers) you can join the VATSIM-UK division at http://www.vatsim-uk.org .

Joining VATSIM-UK is simple and only takes around a day. You will not need a new user or password for VATSIM-UK as they get their data from the main network database.

Once you are a member of VATSIM and VATSIM-UK Division, simply install your connection client (Squawkbox 3/FS INN (more details on the ‘New Pilots’ section of the vatsim-uk site)) then load up your FS, start Sqauwkbox3/FS INN and connect to the vatsim-uk network.

If want me to explain it further you have me on MSN Warren, see you around!

Regards,
Martyn.