With that in mind 06gs, it would benifit you greatly to do some major research in the breed before hand, although clearly you are here, so that is a start
Dobermans can be high energy dogs, they are velcroed to their owners nearly all the time. As a first dog, I am very iffy that a doberman is an ideal choice. They are not an easy dog to own. Dobies require work and time everyday. They are not your basic "porch dog", they are active, and if not properly trained and socialized (hey didn't I just get through saying all this, daja vu!) they can be a liability to own. If you have a busy schedule, they are probably not the breed for you. In addition, they are sadly blacklisted by many insurance companies, so there can be troubles there just with your home insurance, goodness knows I can relate to that.
They are also prone to some serious health issues, and that is worth checking out in itself. http://www.dpca.org/gendisease.html
I'm not saying all this to down Dobermans, it's just fair to say they aren't for everybody, or even most people. And with the commitment involved, it's worth it to know what you are getting into, especially even considering one as a first dog.
May I ask what attracted you to picking a doberman as a breed of choice?