It seems to me that connecting two appliances, each plugged into 110v, via sockets/ports which are powered via same, would be like taking an extension cord with two male plugs and plugging it into two wall sockets, blowing/shorting out everything in the house or in this case one or both computers. What am I missing?
Two things. The peripheral ports on the computer aren't power sockets; they're data connection plugs. And the computer itself doesn't run on 110 volts. The power supply steps the wall current down to 12 volts and 5 volts. You could stick your tongue in a USB or FireWire socket with no ill effect (well, to you, anway).
Assuming that I can connect my two computers, what should I see on the screens of each? And how do I physically manipulate files/folders in OS 9 to get them over to the new iMac's OS X? Find them via an icon and drag them from one Desktop to the other?
Depends on how you do it.
The easiest way is to use FireWire target disk mode. Start your old computer in target disk mode. That basically gives it a lobotomy; it turns off the actual computer and makes your computer into just an external hard disk. Plug it in to the new computer. You will see your old computer's hard disk appear on your desktop. Open it and copy files to the new computer's hard disk.
Just as an example: What's an iTunes window? And how would I select the stuff (2 folders, as mentioned earlier) from one system and stick it in another?
The iTunes window is what you see when you run iTunes. You can run iTunes, then open your old compute's hard disk, click on the music files, drag them right into the iTunes window, and let go. That will copy the music onto your new computer.
And someone warned me about something called "permissions", to the effect that every file/document that comes from one machine to another needs to have access permission dealt with individually - which would mean manipulating thousands of files/documents in some way. What's all that about?
Since you're coming from OS 9, you don't need to worry about that. OS 9 doesn't have permissions.
Does the new iMac and/or OS X 10.7 have something like OS 9's Disk First Aid which will fix things in case I do something stupid or perform an "illegal" function or the system crashes?
Yep! It's called Disk Utility.
EDIT #2:
I just searched through Apple Help on my iMac running OS 9 and apparently there is no way to transfer files from it without some other intermediary (such as an external storage device). To say that I'm discouraged by the whole business of trying to upgrade would be understatement to the googol power. I'm about to forget about the whole business and not even bother to take the new one out of the box.
I don't know that that's true. Does oyur old computer have a FireWire jack?
