Hi, jedast !
The program called Norton Ghost will do the job. You have to boot from a dos diskette in order to run this program.
I assume you've already installed the new drive? If so install the old drive as well (there should be two 40pin connectors on the ide cable going into your hd. One should be plugged into the new drive, plug the other one into the old drive). boot your computer up and the drive should auto detect. If not hit delete during the initial startup and go into the bios. Auto detect the drive from there and then reboot. There are a lot of other things that could go wrong but that should get you started.
It depends on how you put the jumpers and how you connect them. I would recommend you leave your original drive as master and the new one as slave, or even better, connect them to separate IDE channels.
your hdd should have come with a util to do this
i know that ibm western digital and maxtor all do they can also be downloaded from their websites, best of all this is free
(*cough* norton ghost *cough*)