I'm terribly sorry if I put this in the wrong place. Anyway, I'm been practicing a lot more and I've decided I wanted to try some recording. I'm not planning on professional recordings, but just some home recordings where my voice sounds decent. My only options right now are my built in labtop mic and a headset mic, both of witch make my voice sound awful. So I'm hoping to purchase a cheaper microphone that I can use to pick up my voice, and perhaps my voice and guitar at the same time. I assume the Cadion or whatever is what I need? I am also hoping for something that plugs in my computer for rough recordings. I am around the $100 range. Thanks!
You're in the right place. Have a look at the Interfaces thread first, to see why line-in is a bad idea. Unfortunately, it looks like you will need an interface; to get any decent level of quality, you'll likely need a condenser mic, which requires a separate power supply because of how it works, which a good interface (like the Scarlett 2i4 in the Interfaces thread) will have.
For your budget your best bet is something like a Zoom H2, which is a portable recorder that can also function as an interface. If you use it right you'll get a decent vocal sound from it, I think better than an interface with a cheaper mic. It's worth a look!
A USB condenser mic would be the simplest, cheapest method.

But since you also mentioned recording your guitar, you may find a separate interface more useful in the long run. You can plug in an electric guitar/bass/keyboard directly, or use any mic you want, giving you better quality and more flexibility at a slightly higher initial cost.