How do I get virtual airlines, like delta, on fsx and make scheduled flights.

What do you mean by virutal airlines? Do you mean FSX Aircraft with different paints, or flying with other people, such as communicating with other real pilots and ATC in a virtual network?

I really dont want to advertise that obvious, but if you go to http://www.wdwva.com you can take part in a very nice airline that is part of a server community (FSXWorldwide). The people on there will help you set everything up (you can join the Teamspeak and ask questions, the IP is on the following website: www.fsxworldwide.co.uk
Any questions, feel free to PM me

Go to VATSIM.com and you will find what you want.