I’d like to record some classical guitar. I have Garage Band and a couple of generic USB mics. I also have a two-channel M-Audio preamp/audio interface, so recommendations for better mics for the amateur or “prosumer” would also be welcome.
The standard configuration is 2 mics, one pointed at the sound hole (but from an angle, not directly out from the sound hole) and one up on the neck around the 12th fret. The first mic will give you the tone of the guitar (mids and lows), and the 2nd one adds the highs as well as some strumming and fret noise.
As always, this is just a starting point. Always test your setup and make sure your happy with the sound you're getting before recording a bunch of takes. I like to walk around the guitarist and see what it sounds like from different angles and positions, and then try to place my mics to capture the sounds I liked.
I respectfully disagree with mic-ing the neck of the guitar in classical music, the fret sounds of a guitar are most likely considered disturbing. My personal favorite: create an XY-looking stereo pair (XY = make the capsules touch each other, and have them in a relative angle of 90º) with omnidirectional SDCs, and pan them 100% L and 100% R This sounds ridiculous, but above 10KHz OMNI mics aren't really OMNI, so below 10KHz all sound gets into the center, while the high frequencies spread widely over the stereo image. This works fantastic when done with DPA 4006, but these most likely exceed your budget very far. (They are $1800 each). Though, it can be done with any omnidirectional SDC.
If you don't feel comfortable buying omnidirectional SDCs because you are not sure whether you are going to use them, you could try the same setup with cardioid-pattern microphones (which - if you are unfamiliar with directionality patterns - are more directional than OMNIs), but then I would play around a bit with the angle, 90º might be just a bit too much.