Before you go twisting truss rods and adjusting saddles lets check a few things first.

If you are getting a buzz on the lower frets there is a chance the nut is very worn and/or poorly cut. Simple way to check.

Push hard and release the string right in front of the nut. This is just to assure the string is well set into the groove. Now depress the string between the second and third fret. You should have just a trace of space (a paper width) between the string and the first fret. If the string is hitting the fret the nut is cut to deep.

Look at this site for further info.
http://frets.com/FRETSPages/Musician...nutaction.html

You can also check the Frets.com site for further info on saddle adjustment, action, neck relief, etc.. Even if you opt to have the guitar set up by a pro, it's good to have an idea of what the issues might be.