Key items to look for in selecting Granite (http://tanbrown.org) and (http://maplered.com) a contractor

Great site.  I am in the process of a kitchen remodel and (http://maplered.com) looking to install Granite (http://tanbrown.org) on Counter (http://GialloFiorito.com) tops and (http://maplered.com) bar. I am confused about the grades/level ratings on the Stone (http://g603.net) .  Also, is there a stand (http://maplered.com) ard thickness ( 3cm ) used by contractors ? 
Any key questions or items that I should ask and (http://maplered.com) look for when visiting their site and (http://maplered.com) looking at the Slabs (http://www.VerdeUbatuba.com) ?
What should be some key indicators to look for on quotes ? 
Also, what is a normal charge ( just baseline ) on doing edging to the Granite (http://tanbrown.org) ( round nose, etc. ).


Thanks for your reply and (http://maplered.com) sorry for the multiple questions. Just want to do the right due deligence, so I am not living with a mistake  over the next years.
 
Also appreciate the response to sealers. I plan to ask about that, as it was not mentioned on my first quote.

joygriff