There are various things you should do before you actually move over to TIGER.
1) Purchase a copy of Tiger. Well OK, this could the second last thing on this list but who can wait?! ::-0
The other items should be done before you bring your Tiger DVD near your computer.... just to be sure.
2) Back up your important data. There are various ways of doing this: - burn important data to CD: the definitive source of help for this is.... the HELP menu. In the search field select "Search all Help" and type in the word "burn". This should get you on the way.
- burn important data to DVD (if you're lucky enough to have a DVD burner) (see previous HELP suggestion)
- copy important data to another hard drive/computer. There are various ways of doing this but the simplest is to connect an external FireWire drive to your computer and use that. You can also connect another computer in "Disk Mode". Search all HELP for "disk mode". You should see an entry for "Transferring files between two computers using FireWire". Check it out.
- if you have a .Mac account, you might also contemplate using the .Mac Backup utility. Backup is free with .Mac and fairly straightforward. You check off the bits you want backed up and set the backup destination (.Mac account, CD, DVD, other hard drive, etc.) and you're off. It didn't seem to list everything I had wanted to backup, however, but it did do things like preferences, iTunes catalogue, etc.
- lastly, is Carbon Copy Cloner, a free utility (although donations are accepted) available at: http://www.bombich.com/software/ccc.html The downside of this is this won't work under Tiger... yet. The author is making changes even as you read this. I haven't used this but have heard people talk about its use. It is easy to back up everything, apparently, and restore it later..... to versions 10.1-10.3. Like I said, 10.4 is coming....
- all of the above. Just how important is your "important data" to you?!
3) fix your hard drive. Chances are that things have gone slightly awry on your drive over time and you may not be aware of it. Apple provides the "Disk Utility" to handle this. Now you can find this utility on your hard drive but to be able to fix anything you must boot with your original OSX install disk 1 and launch "Disk Utility" from that menu. If you launch from your local hard drive you will be able to Find problems but not Fix them. HELP can be helpful here as well if you search for "disk repair" and also check out the HELP within "Disk Utility" itself.
I would suggest that you do both "Repair Permissions" and "Repair Disk" for you drive since they fix different things.
4) Now that you've spent countless hours backing up (you did back up your important files that you can't recreate and won't be able to work without, didn't you?) and fixing things, now you're ready to install Tiger.
You have basically two choices (well, technically three but two are just variations on a theme).
You can "install in place" (referred to in the "Installation and Setup Guide" as "Upgrade OS X". This basically deletes anything to do with your old system and installs 10.4 in it's place. The variant of this is "Archive and Install". This will install the complete new system for you but first it archives your old System, applications, etc. (into a folder named "Previous System) and then does the install. You won't be able to boot from the "Previous System" but you can copy things out into your new Tigerly world.
There is also a "Scorched Earth" option - well, OK, Apple doesn't call it that but, well, you get the idea. "Erase and Install" does just that. It erases your entire hard drive (well, the one you select during the install process) and then installs 10.4 into this pristine space. The upside is that you are pretty much guarenteed no hard drive problems (yes, I know, you did the hard drive repair earlier.... but what if...) and you are definitely guarenteed that OS 10.4 Tiger will be the first things installed onto this hard drive - which might make it perform better since it now has the choice real estate on your hard drive.
The downside? No user IDs. No applications. No preferences.... other than the defaults that come with OS X. If you've used the .Mac Backup utility, some of this can readily be restored.... but probably not all of it. For example, user IDs must be created before you can restore the preferences for same.
All of that having been said, it's not a complicated process. It just takes some time to be safe.
FYI: I did the Archive and Install choice. Things are working well so far and I'm happy (so far) with the performance I'm seeing.
Good luck and happy Tiger'ing, Wayne Billing
You can also find an audio version of this at: http://home.cc.umanitoba.ca/~billing/casting/Install%20Tiger%20Prep- postprod.mp3