I'm looking to turn an old dell dimension 2400 (yes I know it's ancient, but all it's parts still work) into a fairly small teamspeak server for my friends and I. First question, do you guys think that computer will do the job effectively? And second question, which version of Linux would you recommend? I'm pretty much a noob to Linux so something that doesn't require a ton of knowledge is preferable. thanks in advance for any help.
Try Manjaro. Use the XFCE link and it'll probably be 32-Bit. As an alternative mumble is similar to teamspeak, but also Open Source. Happy Hacking!
http://manjaro.org/get-manjaro/
I don't know what distro would work best for you, but I will suggest that you use mumble instead of TeamSpeak. Mumble (and murmur the server) are both supported in the official Arch Linux repositories, so I'll assume that mumble and murmur are available in the official repositories of most other distributions. Also, in my time working with both TeamSpeak and Murmur I have found that the former is harder to setup and keep running. This may be something that has only happened to me, but I would still highly suggest you check out murmur/mumble.
Debian is known for its server ability, but Manjaro would do fine, Pacman is generally better than Deb, Personally I would use Mageia 4
I wanted to start learning Linux about a week ago, the best way that I found but haven't tried yet is trying out different distributions using VirtualBox. It basically lets you set up virtual computers on your computer, and you can install different operating systems on each one. You have to give your virtual computers ram and hard drive space. You can mess up as much as you need to and it won't affect your actual system or computer, only the virtual computers which you can always reset. It's also helpful for people with family members that don't know how to use the internet safely because you can just let them use a virtual computer, this way if they accidentally download some bad stuff or get a virus etc it will only affect your virtual computer. I think I will try Debian first.
First, your machine has plenty of power for a group of friends. Unless you have 20Mb upload, you will run into a network bottleneck before you run into a CPU bottleneck. I started out with Ubuntu, and I recommend the Lubuntu flavor for first starting out. It'll get you on your feet for a first server and easily supports Mumble/Murmur (I recommend those as well), TeamSpeak, and many others like XMPP (If you go this route, I suggest Prosody + Jitsi). I am simply an amatuer server hoster, so take what I recommend with a google of salt.
I've got a 100Mb NIC in there so I should be good, and gonna be honest I laughed pretty hard at the google of salt part