Hiya Stevie
Strangely enough you don't need two drives to copy dvds; I have two but only use the one. There's various pieces of software available to make copies. The best, I think, is DVD Cloner III. Don't be tempted to copy directly from one drive to the other (on the fly). Copy TO your hard drive then copy FROM the hard drive. Some software deletes the copied file after it's burned it, but naturally disable this if you want more than one.
Like you I bought a dual layer dvd writer, but to be honest, I don't really think it's necessary. Even a three-hour film is good when recorded on a 2-hr 4.7Gb dvd.
Have a look at this
http://www.afterdawn.com/ OR
http://www.doom9.org/index.html?/mpg/dvdshrink 31-main.htm
Shame I can't leave my email addy.