Browse this gallery and you will be able to see different setups for dual monitors. All i can say is if you only have a single monitor right now , you will be leaving wanting to add more.

I currently run 2, and now want 3 maybe 4 or 5.....

What can i say!!!

http://www.realtimesoft.com/multimon/gallery_browse.asp?date=desc&mon=desc

If you do editing on a normal PC and you have one or more
laptops lying around you can also turn them into an extra monitor
(yes, no screen replication, but multi screens) with this software (http://www.maxivista.com/)!

I've been testing it out and it seems to run pretty good. Works
flawlessy with Vegas 4. I did have to run the screen (on my laptop)
in 16 bit mode though [performance issues], but that's not too
bad for video editing.