Windows 7 is so much easier to setup than older versions of Winodws, so doing it yourself is less risky than it used to be.  Here's what you should do:

1. Physical Assembly:  Unpack everything, and you should see a nice graphical card or poster that shows you (with pictures!) what connects where.  For notebooks, this usually means connecting the battery, and plugging the computer's power cord into the side or back (and the other end into a handy outlet).  For desktops, you will also need to plug in the monitor (and sometimes speakers), and connect the right cables from your monitor, mouse, and keyboard to the back of the CPU.  Just follow the instructions on the setup poster.  If you have a new printer, it'll have its own setup poster, but don't connect the printer to the computer for now (or better yet, you smartly purchased a wireless printer!).

2. Initial startup:  Press the power button to the computer (if a desktop, power on the monitor and speakers first).  Wait till the Windows setup screen comes up, then follow the on-screen directions.  Be sure when you create a user account to give it a password, and if asked, give the Administrator account a password.  It can be the same, or different (especially if you will have multiple user accounts for family members, etc.).  Continue with the setup until it is complete and you've restarted the computer and logged into your user account.

3. Now before you start using the computer, you need to install updates, helper programs, and any software you plan on using.

   1. Updates:  Go to Windows Update (in the Start menu under Programs), and take all the recommended updates. You may have to do this several times, restarting the computer.  Keep running Windows Update until there are no more recommended updates available.  For the optional updates, we generally take all but the Windows Live stuff (unless you're going to use those services), but take no updates to your hardware or attached devices (printers, for instance) - you'll get those from the manufacturer's website - and there's usually a link on the Start menu somewhere for those (this varies by manufacturer).

   2. More info coming shortly!

Of course, if you are totally stuck and need our help (and are in the Washington DC metro area), we'd be happy to help you.  Please