Getting rid of the buzz

acoustically or electrically?..
a few things to mention is the placement of the fingers relative to the fretwire.. you will want to get close to those wires to produce a better cleaner tone. attempt to play a little lighter.. a strong strum and a strong fretting hand can work antiproductively. if you are a beginner these things will work out over time.. as you practice more
but on the flip side i like a little buzz and sqeek in my acoustic playin adds to the ambience.

also another thing to keep in mind is the setup of the instrument.. if your action is higher it may need a lil lowering to aid in the desired tone to be achieved

It's an acoustic. What does " If your action is high it may need a little lowering" mean? What's my action? And how do I lower it?

action is the releif of the strings off the fretboard.. if there is to much space you must push the strings down more which will add to more difficulty in playing fretted notes. action can be changed by several things.
use lower gauge strings which will add less tension to the guitar neck.
adjust the truss rod in the guitar neck
shave down the saddle.

i would not suggest altering the truss rod until you research it a bit.
you can always take it to a shop for a proper set up if available

you may want to look down the neck of the guitar to determine the bow in the neck.. look from the bottom of the guit up to the headstock, see if the neck bends up tword the ceiling or back to the ground. that will help you determine what needs to be adjusted.
personnally on most of my guitars i like a lil bit of releif in the neck.. ( a slight upturn)
and i shave down unbleached bone saddles to help with my action

Take a look at the links on here:
http://www.frets.com/FRETSPages/pagelist.html (scroll down) - theres a lot of information including pictures which you might find really useful, I know I did (and do come to that).