http://www.mguitar.com/guitars/choosing/index.html

It is difficult! i know... Have only a few tips for you. If you like strumming and deep basses, choose a D or J model. If you like fingerstyle go for the OM or 000 models. Consider a 12 fret body for pure tone. A cutaway for acces, think about the neckwidth, the scale, the woods. In general; Mahogany is warmer, Rosewood has more dynamics, Madagascar and Brazilian have got it all, but madagascar is expensive and brazilian rosewood guitars are priceless..