A distro is a wrapper, that is where all the bells and whistle come from. Linux is as plain as a piece of paper, and you hold the pen that is given to you from the distro. So the breakdown, of the 3 distro types. Now don't be confused a type is just that, there are more distros then 3, but they all are classed in 3 types. Now your choice should be directed by what type of reason you are using linux in the first place. IE server, desktop, streaming share, etc...

Slackware Based - text based, comes with a gui, but the installer is all text based graphic installer. Has a package manager, but you have to find and make it work with your Slack version. This distro type is NOT recommended for new linux people.

Red-Hat Based - text/gui based. I do not know much pertaining to the ACTUALL red hat these days, as I gave up on them after RH 5.0. Has a package manager, using RPM (dot rpm files).

Debian - This is the type that is being followed, with Ubuntu, Puppy, Linspire, etc.. For a new Linux user, I would recommend one of these. Since most of these types of distro come with a live cd, this will allow you to play with it without installing it.

Now the above being said.. if I were to recommend any distro to any new linux user, I would have to go with one that I know they would feel most unafraid of. That of course would a Debian type Linux. I would also recommend to play with a live 'cd'. It is easier to go get more cd's then to reinstall you computer. With the live cd you'll get the chance to play without needing to worry about breaking anything, as it is running from a cd and does NOTHING to you hard drive. (BUT it will if you make it)

As far as package managers, you have to read about each, for the distro you are looking at. IE, Synaptec = ubuntu's, ePackages = Gentoo, Slaptget/Swarat = Slackware, and so on.

Remember Linux is the bare bones of the OS. You are researching the Window Manager Distro, and Package Manager. Each distro has it's own distro package distribution method.

The more informed you are the better you will decide. Don't rush your choice, take you time. Get opinions from some of your co-Linux friends, ask them what they like or don't like about a distro you are looking at.

IE. I install (KX)Ubuntu for the simple fake that I can have it up and running and anything i need installed for the client in about 30 minutes. - The only using it for docs and email.
KUbuntu = KDE, Ubuntu = Gnome, Xubuntu = XFCE4
They look and feel much differently. If you choose this route, I would recommend going with the one that looks the best to you.

I install Slackware and Gentoo for my servers, Slackware is used if I need the server up right then; I can have a Slackware based server up in around 20 minutes. Gentoo on the other hand, I take my time, as every from install is built right from the beginning, and if done quickly, can be installed in about 4 hours.

So you see, the distro does make the difference.

Hell I might make a blog about this now... feels like I already did.