There's more than one way to skin that cat. Acoustic guitar can be mic'd with 1 or 2 small diaphagm mics, 1 large diaphragm mic, one of each, or a ribbon mic. It's a matter of taste and budget. Give us some idea of your budget, because the answer to your question runs from $50 to several thousand. Also, do you have phantom power? You will need a preamp or a mixer. For dirt cheap, I like Oktava MC012's or Marshall MXL603's, in pairs, or one Studio Projects B-1. For a little more, I like AKG C2000B. In the up to $500 range, consider a pair of Studio Projects C-4's or one Rode NTK, also a very nice vocal mic. What I really like? AKG C414B-ULS, just one on the 12th fret. I have more expensive mics, but nothing I'd rather use on acoustic guitar.-Richie