Buying an acoustic guitar......want some tips from you guys?

Hello,everyone.Well,to begin with,I am a beginner.No practical knowledge about guitars.I have been doing some research about guitars and brands.So I have some knowledge about them.But still I am not confident.I have no one else to help me.So I want to know what do you guys look for while buying a guitar?I am not talking about brands here.And what are the things that I should check befor buying a guitar(like bending of necks,fret buzzing,etc)?Thanx in advance.BTW,I would be playing classical and latin more(i mean slightly more) than rock,so should I buy steel-stringed or nylon-stringed?Thanx again.