1 mic recording.

[Seeker]

If it were me, I'd start about 12 - 18 inches away from the guitar, capsule at the same height of the guitar facing straight on pointed at the 12th fret. Depending on the guitar / sound you're looking for, you may want to move the mic slightly more toward the body of the guitar.

I've used this technique quite a bit with small diaphragm condenser mics when recording acoustic guitar that was intended to fit into a larger mix. If its a solo thing you may want to try a large diaphragm condenser or ribbon.

 

[rainy-taxi]

To me it also depends on what kind of sound you are after. How much "direct" sound do you want, do you want more or less bass in the sound? A spot which I found interesting is having the mic close to the player's right ear (assuming it is a right handed guitar) but the sound has less attack as you don't pick up the direct strings, only indirect.

 

[CalavoBob]

There's a very natural sounding spot most people don't know about to place a small diaphram condenser mic on good acoustic guitars. On a right handed guitarist its on the rear of the guitar just below the right armpit where there's a lot of the guitar back exposed. Put the mic about 3-4 inches away pointed directly at the back of the guitar. You won't pick up any bass boom like you can get from the hole when miking in front and its a very balanced sound with surprisingly good highs. The only drawback is if you have a player that turns around on a rotating stool because they might hit the mic. I've blended this with a front mic too for an interesting spread.