So ive been recording by connecting my guitar into my amp into my computer... would i increase the quality of my recordings by using a DI?... and Would i just run my guitar into the DI and into the computer?
All that a DI box does is convert your signal from an instrument signal to a line signal, which is what the Line Out on your amp does as well. Unless you already have one to try it out with, I wouldn't recommend wasting the money.
You would increase the quality of your recordings using an audio interface, however. A small USB unit would probably do the trick for what you need it for. Take a look at the EMU 0202 for a cheap option.
I'd only consider DIs if you use an acoustic electric guitar or a bass, if you have a great soundcard that can't accept a guitar input (and you want to use software amps), or if you plan on reamping. Radial, Whirlwind, and BBE are the brands to look into. As stated before, you'd go a lot further with a good interface (which oddly enough frequently include a DI box).