EQ Acoustic Guitar

Low End 80 Hz
Place a steep high - pass filter at around 80 - 100 Hz to leave the low end for the bass guitar and the kick drum. If the Acoustic Guitar is played strumming as a rythm guitar the high pass filter is often increased up to about 200 Hz to make it sit better in the mix. 
If boominess is troubling your recording you can also use an extra bell curve with a narrow to medium Q and turn down (Cut) the gain until the boom is gone.

Bottom 80 - 100 Hz 
If the acoustic guitar has a prominent role in a sparse mix ( like with fingerpicking for instance ) and the sound is too thin you can put some bottom back into it by very slightly boosting between 80 and 100 Hz. If the guitar has to much boom in the low end you can take away the boom by cutting at around 100 Hz. If the acoustic guitar is strummed this frequency range is often taken away by a high pass filter at around 160 - 200 Hz to kill the low end noise of the strumming and to leave the low end for the kick and the bass.

Body 200 - 250 Hz
If the acoustic guitar is thin and without body you can boost slightly between 200 and 250 Hz with a medium bandwidth (Q). This is often combined with a cut at around 100 Hz with a narrow to medium bandwidth bell curve EQ or a high pass filter up to about 200 Hz to give the kick and bass more space 

Metallic 500 - 800 Hz
If the guitar has too much of a metallic quality you can take away some of the sharpness or shrillness by cutting between 500 and 800 Hz with a medium to narrow Q. This is used very often to get a better quality acoustic guitar sound.

Clarity 2 - 2,5 kHz
Boost only a couple of dB with a wide bandwidth between 2 and 2.5 kHz to give the Acoustic Guitar a bit more clarity and presence in the mix.

Air 4500 Hz
If you want to give the Acoustic Guitar some Air you can use a shelving EQ at 4500 Hz and boost 3 to 6 dB.