virtualbox.org

I'm trying to set it up and I'm lost. First of all, what I want to do is run the Steam program in the other virtual OS. Is this what Vbox is for? If you can do this, then I can continue.

I got to the part where it asks what media do you want to install the OS from and I can't get passed that.
EDIT Ok it looks like I need to either have the actual OS CD or an ISO. I have a built in recovery drive. Is it possible to use that? Also, am I understanding this correctly?

Your first move should be to understand what virtualization is and what it can do for you.
The next step would be to read the manual.
VBox is not a games machine

As Frank has said, you have probably misunderstood what VirtualBox is. It isn't (as such) an emulator like DOSBOX, it is a Virtuliastion Platform. This means you can run Virtual Operating Systems in a window (or command-line).

Virtualbox is currently asking you to install an operating system to use, VB does not provide one automatically. You will not be able to use the recovery partition for your computer/laptop (and if you can it would probably be very difficult and illegal). Also while games can be run in VirtualBox machines can only be allocated a small amount of Video RAM (which AFAIK take from the Virtual Machines RAM rather that your onboard or extra graphics card).

I don't want to run games on it. Well I do but that's not the big point. For those of you unfamiliar with Steam it is a game client. You can only have 1 open. I have different accounts that I would like to open up at once on the same computer. The only other option would be to have a couple of computers on at once. I was trying to run Steam and then run a game just to trade between my accounts. I don't plan on doing serious gaming. Would this be possible with Virtual Box or any virtualization software?

Does Steam need to run on a Windows or Linux machine? Or is it its own OS machine?

Steam needs to run on Windows or OSX. It is just a program.

I am fully aware what Steam is, yes.

I would expect what you are trying to do is fully possible, you'll just need to install a virtual OS in the machine and then install Steam on that as well.

But games that are attached to an account cannot be played on the Host if the account is not the same for that game. You can't 'magically' play game Y on the Host for account Z that is logged on in the VM, while user X is logged on on the Host.