I want to adopt a new dog from a shelter but dont know what kind
That is great!  I have wonderful chocolate lab,   do you have a backyard?
I live out in the country so I have lots of open area around my house.  I had a black lab who just showed up at my house years ago and never left.  
Perfect. Would you are looking for a companion for your dog? do you want a small or a large dog? 
My lab died last year.  Dogs long association with humans changed their diet to be able to eat more carbs than other similar species?  My lab certainly ate anything!
How sad! yes mine too, but I still try to complement his chow with more protein.  I think that is healthier for dogs and people.  So, have you adopted from a shelter before?
No.  All of my animals just found me.  I have looked at internet sites which have databases of thousands of pets in shelters