Update: I have leopard up and running. It went very smoothly on my imac. I just followed the archive and install method and updated my software as soon as I booted up.
I thought I'd talk a little about what to look out for and what's in leopard. First don't be in a rush to get leopard, as with any major upgrade-I think most people by now know that waiting a week or two is a good bet to find out if the third party applications will run smoothly or not with leopard.
This will keep you from spending endless hours or days trying to get this to work on your main computer's software/hardware. Then when the time is right you can upgrade with little or no problems. Or maybe you will wait for the first upgrade from apple to fix any known problems. Let's hope that there won't be to many issues to deal with.
The Apple website gives you a good feel for what's in leopard and the "maccompanion.com" has a series of articles going into detail. All links can be found on my blog. Here is the link to system requirements need to work in leopard. If your mac doesn't meet the requirements, you will have to upgrade. JonL
leopard system requirements
Update: Adam Christianson did a podcast on "how to get ready for Leopard".
I added the link for those who want to make the transition as easy as possible.
And finally, from Macfixit; an article on preparing Leopard installation-before and after.
Problems updating leopard: From macfixit and Apple website I see this being the best way to upgrade. Archive and install. Here is why. JonL
Archive and Install choice
This option moves existing system files to a folder named Previous System, and then installs a new copy of Mac OS X. This option is available only for volumes with Mac OS X already installed. Usually, if you select this method, you will want to also select (check) "Preserve Users and Network Settings" which imports existing user accounts, home folders, and your network settings into the new system.
Make sure you run disk utility to check for any disk problems before you install Leopard.
failure to boot