I am attempting to fix a friends iBook G4 that is running Leopard. First of all based off her stats she should not be using 10.5 at all, but that's my opinion. But I am going to ignore that an attempt to fix this pos. I was told that she installed some software updates and now her finder no longer opens (just crashes) I can not even see it open. Also the hard drive is not displayed on the desktop. The strange thing is though that I can pretty much get to all the files or programs via spotlight, Safari, MS Word, Terminal, Disk Utility. I am pretty much in the dark here so any assistance would be appreciated.

I doubt you are 'in the dark.' I think you are just unsure of Leopard. Stop thinking the problem is 10.5 and think about what might have happened during the updates. I think there is a major disk corruption and it is getting worse.
Back up as much as possible. It may or may not be required to do a clean install.
Start up from an external drive.
Run Disk Utility on the iBook drive and repair it. If it repairs, you are in good shape. If it says it can not be repaired, then you are in for a reformat and reinstallation.
You should do this before the disk is not mountable, or the difficulty will become much worse.

Good luck. There are lots of accounts of people who run 10.5 on an iBook G4, so I guess it works.
Here is a quote: "installed on my ibook early today...absolutely flies, definitely recommended
The menu bar isn't transparent, time machine background doesn't 'move' but other than that it's nice and speedy."

http://forums.macrumors.com/showthread.php?t=374283

I hope it works.