Adding 3rd hard drive and swapping Video Card

The Power Mac G4 that I just bought has 2 120 gb hard drives. I need to add a 3rd larger drive. How hard is it to add? I'm a newbie when it comes to macs but I was able to take out the original dvd burner and put in a new Dual Layer dvd burner so I'm not completely hopeless. I would assume the hard drive is even easier. If someone can let me know step by step instructions that would be so awesome!

Also, I have ordered a new Radeon 9600 Pro 256MB PC + MAC Edition to replace the orginal card. I did my research and know that this card is compatible with my MDD G4. So I also need instructions on how to swap these cards out.

I appreciate everyone's help!!

I don't know how you have your MDD setup. Mine is setup where the two superdrives are connected together using the same IDE cable and it's connected to the logic board's front connector nearest the inside of the case. I have the 500GB on its own IDE cable (supplied with the computer) which connect to the second IDE connector just about the IDE connector for the optical drives. I did this so the two HD's weren't so close and wouldn't overheat.
The original 80GB HD is where is was originally mounted in the rear of the case and connects to the rear IDE connector.
My MDD came with a spare set of screws and IDE cable, so I assume yours does too. If you're connecting the new HD below the optical drive sled, the spare sled for the HD comes off with a little gray latch. Push the latch down and the sled slides right out. There should be four backup screws attached to the sled for the new HD. Attach the power cable supplied and IDE cable and that's about it.
I assume the new HD will have the jumper pin set for master. Read the diagram and make sure you set it for slave before doing all of this.
I just installed the 500GB HD on Friday and it worked fine. When I started up the MDD for the first time, I had to format the drive using disk utilities because the Mac didn't recognize it.
It's about a 10 min job.
PM me if you have any questions. It's pretty simple though.
Bryan

Can I use a SATA drive on my setup? Comp USA has a 500gb WD drive for $119.