I think I accidentally deleted my computers ability to make sound. Uh...how do I get it back?

It dipends on your OS. For instance, Windows XP Home. Vista Business, Windows 7, Ubuntu 10 Desktop etc…

See if this works, go into control panel, and click ‘administrative tools’. Then click on ‘services’ and scroll down until you see Windows Audio. Right-click, start it and set it to automatic.

What do you mean by set it to automoatic?

By the way, I use Windows XP on a Dell Inspiron 6000 from about 2005

When I go into sounds and audio devices properties, it says “No Audio Device”

Try this link
or this one

Open msconfig and choose a restore point before you deleted the sound and it should be restored as if you never did it.

Sounds like your computer may be bugged/infected with viruses..
There is a relatively universal driver for integrated motherboard sound called the AC 97’ audio driver/codec. Give this a try and if not you can remove it through windows add/remove programs. Hope this helps you some.
http://download.cnet.com/Realtek-AC-97-Audio-Driver-XP-W2K-W98-WDM-driver-VER-5-10-0-5554-zip/3000-2110_4-210198.html