How closely does it parallel windows? At this time, everything you could find for Windows has either an exact counterpart in Linux, or something close enough to it to call good. The deal is that you may have to take some time to learn how to use it.
You don't have to be a programmer or network administrator to use linux.
Most modern distributions of Linux look pretty much like Windows and function more or less the same. If you're into listening to music, Linux will do this just fine. If you're into basic web surfing, Linux can do this no problem. If all you want to do is send a few emails, Linux won't have any problems doing this either.
The biggest difference between Linux and Windows for most users is the process of installing new software. .exe files do not work on Linux (well, not without special software called an emulator, but that's beyond what you want to do so it doesn't matter). In Linux, you're going to install software by two main methods - packages and source tarballs.
Packages are the easy method. Depending on distribution, you'll use a variety of different packages. RPM is one common package solution. They're more or less install files that you'll install either with the command line, or (with most modern distributions) an RPM Package Manager GUI. RPM is most commonly found in Red Hat distributions of Linux, though many, many others use RPM as well.
The other main package style is called DEB, short for Debian. DEB packages can be installed by command line or (again, with most modern distributions) a Package Manager GUI. They're pretty much like RPM files, just packaged differently. You can even, if you have the right software installed (alien), convert an RPM to a DEB. You'll probably never need to do this.
If you're new to Linux, you're going to want to choose a newbie's distribution. For example, I wouldn't suggest Slackware for a new Linux user. Slackware just isn't designed for a person to cut their Linux teeth with. Slackware does not automagically set up many things that a newbie doesn't know how to set up. It's not designed to do it.
For newbies, I would suggest something in the Mandrake lineup, Red Hat lineup, or possibly Ubuntu. I caution you that for a Ubuntu setup to play a lot of the music you want, you'll need to learn how to use repositories and apt-get quickly. Out of the box, Ubuntu will not play your music. From what I've heard, neither will the Fedora offerings from Red Hat, but don't quote me on it. I gave up Red Hat long ago, around version 6.
Lastly, if you're not terribly comfortable with not knowing your Operating System well at first, you can dual boot your machine. This will allow you to learn Linux at your pace, but still retain your Windows Operating System that you're familiar with in case you break something in Linux accidentally, can't figure something out, or turn out that you just don't like it.
Happy Penguining.
