Help!

[SuperGeek]

Uh oh. I'm in the blender now.
Ok, here's what happened. I was using the Add/Remove to download some
files, while playing Sauerbraten (Cube 2). Unfortunately, while
loading a map, Sauerbraten crashed, as it has a tendency to do so
occasionally. I was forced to reboot my computer, and I fear that the
downloaded files were badly corrupted. None of the programs I was
installing worked, and now every time I try using the package manager,
the update manager, or anything like that, it comes up with this error
message:

E: dpkg was interrupted, you must manually run 'dpkg --configure -a'
to correct the problem.

E: _cache-> open() failed, please report.

I might have only installed Ubuntu last week, and it was my first ever
Linux distro, but I at least recognized the command  'dpkg --configure
-a' as a Terminal command, which seems to be the Linux version of the
DOS prompt. I put in the terminal command and it comes up with this:

dpkg: requested operation requires superuser privilege

So what's a superuser? I set up this computer, and I gave my user
account full access to everything. So why is it telling me this?
Help!