Should I get another Dog (Pics)

[Badger]

So first off, here's Coco. I've posted pics of her before.


Soon all my roommates and I will be gone from 9-5 most days. So I'm thinking of getting another dog to keep entertained while we're all at work. Any experiences with adding a second dog to the house? Do you think it's a good idea? Coco is a 3 year old Chocolate Lab and gets along great with other dogs. Her companion would be from the shelter. Does it matter if the new dog is male/female? Anyone have good/bad experiences with resuced dogs? Here's another picture of Coco: