I need to clean out tons of old updates, what is the command line I should type in?

If you want to clear out the package cache (and you probably want to, especially if you have a fast, reliable net connection):
sudo apt-get clean

If you need to remove old kernels, fire up Synaptic package manager and search for "linux-image" packages. Click the "Installed version" column header twice, and you should have all of the installed kernels before you. You can safely remove everything except the current kernel you're running, but it's always a good idea to keep the previous kernel just in case...
Once the linux-image packages are removed, then Syanptic should mark the corresponding linux-headers packages as autoremovable and you can purge those too.

Thanks dtl131, I'll give that a try. I just figured as Ubuntu updated things it would automatically remove old out-dated packages. I have dozens of abi. files going back a year and 1/2 that have to be useless and just clogging things up. Kernels I cleared all but the latest 3, just being on the safe side.

For removing kernels, it's unsafe for the package manager to do that automatically, since it would have to make assumptions about which kernels you want..

As for apt's package archive, it was designed with slower internet connections in mind. You could just setup a quick daily or weekly cron job to run 'apt-get' clean if you don't want it growing too big.

Not really sure what you mean by abi files.. (abiword?)