/usr takes up about half of the space in a Linux system. So you can balance your hard drive load fairly evenly between your two hard drives by placing /usr on your new hard drive.
When you upgrade your Linux system it is handy to have /home in a separate partition so that you can upgrade without wiping out your user data.
/home and /usr will not even begin to fill up an 80 hard drive. You get the best disk performance by placing the busiest files in the middle of the hard drive. So I would create a large empty partition at the beginning of the hard drive, then /usr, then /home, and last a large empty partition.
I would use the large partition at the end of the hard drive as a place to keep a daily backup (Set up a daily cron based backup that only copies files that have been altered). I would use the large empty partition at the beginning of the hard drive as a place to install new Linux systems that I am experimenting with or dual booting until they are stable enough to replace my existing Linux system.
My recommendations are based on my existing hard drive configuration which is 12 partitions spread across three hard drives.
___________________________________
Be prepared. Create a LifeBoat CD.
http://users.rcn.com/srstites/LifeBo...home.page.html
Steve Stites