RealPlayer and Windows Media: yes, they work on Mac (download the players). But just as new versions of QuickTime are sometimes a little "late" in reaching Windows, so are new versions of Windows Media. So at times, something using the very LATEST version of Windows Media might lock out Macs (and many PCs) for a while. I don't know much about MusicMatch--if that's DRM-protected then you must burn a CD and re-import into iTunes that way. (Or there may be apps out there to help convert.)
AOL IM: Has a Mac version--but iChat AV (comes with Mac) is AOL compatible. Each has its advantages. I like iChat for its simplicity--and of course, great video if you have a Firewire camera!
Email: OS X has a great built-in program with the clever name of "Mail." If you want Outlook, Microsoft has a Mac variation which they call "Entourage." Other alternatives to consider include Thunderbird (free--it's the mail program from the Firefox browser people). And of course, webmail works on Mac.
Attachments: no problem--you can send AND receive. But as always, the person opening the file must have an app that CAN open it. For Word documents (most of them, at least), OS X can open them without even needing to own Word. (But you can buy Word if you need it--the Mac version of Office is supposed to be better than the PC one.) Pictures and sounds and movies? All use pretty standard video formats. Try
VLC if you need a player for files that QuickTime doesn't like.
Other apps? Look at
http://versiontracker.com and find just about anything you might need--ready to download.
Pricing? The best deal is Apple's student/educator pricing if you qualify. If not, look for special promos on Apple's store page (left side usually) and try Amazon.com--Amazon has lots of Apple discounts and rebates. Other resellers like CDW, MacConnection, MacZone, etc. will all show the same standard price--BUT they throw in freebies to compete with each other. If you can find a bundle of stuff you were going to buy anyway, then you've saved some money. Watch for free shipping, too.
Re iMac vs. Mac Mini: the G4 Mini's a good buy (it's cheap!) but the G5 iMac is a MUCH more powerful machine that would serve you better/longer, if you can swing the cost. And it gives you a computer AND display in zero footprint, essentially. (But you might wait and see if Apple adds that cool new Mighty Mouse as an option with the iMac
Right now, you can get it with the Mac Mini, but if you add it to an iMac you're getting TWO mice, which is a waste.)
Also... if you "aim low" and get the Mini, it leaves you with more money to get a shiny new Mac in a couple years that will blow away anything available today. It's your call. I can even recommend a Dell display with the Mini: they get great reviews (even from Mac users) and are priced low--with big discounts available if you jump through the silly hoops at Dell.com. They're ugly, but they have nice specs/features and come in many sizes. The 20" widescreen looks good to me. (You'll find threads here on Dell display discounts.)
Last but not least, go for more than 512 RAM if you possibly can. (It's easier to add RAM to an iMac than a Mini. And cheaper to buy extra RAM from transintl.com or eshop.macsales.com than from Apple. But price out the configurations because occasionally Apple RAM makes more sense: such as if you have to REMOVE and waste some Apple RAM to put in third-party RAM.)
Welcome
Let us know what you end up with. You're in for a treat with Tiger.
