Hello Marty,
My primary system is a Mac (OS X, 10.3.3), and have been an Apple farmer (pardon the pun) for over 10 years now. Started out with System 6.0.8 way back....
Anyways, take your time, and your system will grow with you. You should already have Safari, and it should be automatically patching itself with Software Update.
I went out and got the latest Real Player, and Quicktime (and also Adobe Reader, and a few other staples of computing, such as Stuffit Expander and updates to MSN and Yahoo IM programs). When you load Safari or your other web browsers, the plug in should be available if you check for helper applications. To be honest, I do a lot of this automatically, and should document it out for you.
I use Firefox because it is faster than Safari, and it also shares bookmarks with Mozilla and Netscape. Dani here is turning me onto Safari. Safari is not completely accepted yet -- it renders pages a bit differently than Mozilla/Netscape. Don't get me wrong -- Safari has a lot of good things going for it.
Firefox also has options for me to block pop-up windows. Every once in a blue moon, I run into a site that I need pop-ups to function properly, so it is a click away, and things are working better, but on the whole, I kill off the pop-up windows.
Mozilla is cool for me too because what I see on Mac Mozilla, I also see on Linux Mozilla, another platform I use almost daily. Mozilla also lets me choose where it is going to store my temp cache files, and I love sending those off to a RAM disk for quick retrieval and quick deletion. The little annoying cache files get cleared whenver I reboot my computer.
NOTE: OS 9's RAM disk was persistant, so you could survive a reboot and the files would still be there. How? It would save the data to the hard drive, and then re-plentish it upon reboot.
I have not run Opera all that much. Found that it would render pages rather funny. I also gave up on IE long time ago.
I suggest that you download Mozilla and Firefox, and give them a run. Compare them with Safari and your IE stuff. You may run into websites (banks!) that require a real IE session to work with, so unfortunately you cannot just kill off IE and delete it. Just like that weird wrench in your toolbox, sometimes you have to grab the obscure thing to make it work.
Give it a whirl, and let's talk tomorrow.
Christian