How do I install 10.3 with 9.1?

Question

I've been always using 9.1 for everything but now I want to try X.3
So, what´s the way to install X leaving 9.1 running as well as now? (I´m afraid of doing it after all the strange things I´ve read here)
I use Quark 3.3, Photoshop 6.0, and Dreamweaver 4, mainly. Which of these can be run in X?
Regards from Spain

Answer 1

I've been always using 9.1 for everything but now I
want to try X.3
So, what´s the way to install X leaving 9.1 running
as well as now? (I´m afraid of doing it after all the
strange things I´ve read here)
I use Quark 3.3, Photoshop 6.0, and Dreamweaver 4,
mainly. Which of these can be run in X?
Regards from Spain
9.1 should work as Classic under 10.3, but if it doesn't, the upgrade to 9.2.2 is fairly painless and is free. Apple has the updaters from 9.1 to 9.2.1 and 9.2.1 to 9.2.2 on their site.
You can install 10.3 by getting a set of 10.3 CDs (there are three, not counting the developer CD) and then installing by inserting the first CD into the drive and launching the installer.
Quark 3.3 is definitely a Classic/OS 9 app. You'll need Classic to use it, and you'll need a font manager which can manage fonts in Classic, too. That means Suitcase 10. Suitcase 11 doesn't do Classic, or at least I was never able to get it to do Classic. Apple's Font Book is not ready for prime time, is not designed for pro font management, and doesn't do Classic. Lino's Font Explorer X doesn't do Classic.
I'm not sure if Dreamweaver 4 does OS X. If not, it's a Classic/OS 9 app.
Photoshop 6 does OS X. It'll work natively, no problems.
If you're going to OS X, you might think seriously about redoing your workflow to use OS X-native apps, such as Adobe's Creative Suite, which includes InDesign. InDesign will read Quark files. Creative Suite 2 ships either as Standard: Photoshop, Illustrator, Indesign, for $900; or as Premeir, which is Standard plus GoLive and Acrobat, for $1300. Quark 6 goes for $700-1000, usually closer to the top end of that scale. Quark 7 is now in beta. Many things are turned off in the beta, they won't tell you how much the release will cost, and you have to fill out a truly idiotic form to get to the beta. (It's now a mere two pages. It used to be four. They want lots of marketting data. I didn't give it to them. They were upset.)
You're going to need to make sure that you have lots of disk space available; OS X's VM is always on, and can eat up to 3-4 GB of disk space without even trying hard if you're like me and have a lot of apps running at the same time, but don't have in excess of 512MB RAM. You're going to need to make sure that you have a lot of RAM; 10.3 won't install with less than 128MB, and you can't get much done with less than 256 or 384 MB. For serious work 512 is a realistic minimum, and if you add more you cut down on the disk space VM will grab. This speeds things up noticeably.
If you have a G3 or an older G4, then you should know that the money spent on bringing that machine up to spec (more RAM, larger hard drive, USB2 card, etc) will be more than what a nice shiny new Mac mini costs. And the Mac mini will be faster and have more RAM and larger hard drive than the older machines, anyway. And it'll come with 10.4, so you don't need to get hold of 10.3 CDs.