I recorded my voice with GarageBand but it sounds very dirty and amateur.
I'm looking at a GarageBand tutorial to learn how to make the recording sound a little more professional and clean.
I use this mic:
I use a proper mic and a DAW (specifically an M-Audio FastTrack), and it totally changed the quality of my recordings.There's a big difference between a proper powered mic (even those of slightly dubious providence, but the one I have linked is good and robust), and built in ones, or even those that plug into a computer mic jack.
I also like to run voice clips through Levelator. For pure voice tracks, recorded with decent gear its magic. It does compression and limiting automatically based off some algorithm, and subjectively, it makes a big difference with almost no work.
You can then mix things as you want in Garage Band.
You will likely need to pick up a better microphone. A decent headset should be quite a step up if you are using a built-in mic. Here is a link to some information about studio quality microphones, a good read that might help you pick out a better piece. Studio Microphone Buying Guide. A lot of mics have a limited range of sound they can pickup, and sometimes this contributes to the 'dirty' sound you get in the recordings since frequncies you hear normally are being chopped out of the recording.
Secondly you will want to check your surrounding environment. If you are in a room with hard walls, such as wood or concrete, the sound can bounce off and interefere with the recording to an extent. Pro studios tend to have the little foam squares covering the walls and ceiling which help reduce the amount of reflected sound.
If you havea tight budget you may want to try surrounding the microphone with some of the sound absorbent foam like in this example. That should get you the best sound quality with the least investment, though it could be somewhat awkward to use depending on the situation.
So I'm kind of in the same boat. I just got this new mic. The mic doesn't have a whole lot to do with making your voice better; it makes the actual recording crisper.
Mess around with the Compressor and the AUGraphicEQ. When using the GraphicEQ, select "10 band" in the bottom left corner then mess around with the little circular buttons to figure out what you need to do to make your mic work for you in terms of sound.
In order to mess with the settings on any effect in Garage Band, you need to click the picture icon FYI.