How to get my dogs ready for a puppy?

I have two dogs, Chester (8 years old) and Max (5 years old) and my dad is going to get a new puppy to go hiking and camping with him. I'm just worried that my dogs will feel left out or something... I know that happened to Chester when my family got Max, Chester got overweight and started being much more protective, and I don't want that to happen to Max or to Chester again.
We're getting the puppy in four weeks, is there anything I can do to "prepare" my dogs for the new puppy?
Thanks <3

?2014-09-02T18:00:15Z

Have u reserved this puppy?? Because if you have u can ask for a piece of bedding or something with the puppy's scent on it and leave It somewhere the other dogs can smell it and when the new puppy comes they will already be used to the smell of the puppy and won't be as surprised about him and are more likely to accept him also when you bring the new puppy home don't make a big deal about it around the dogs otherwise your current dogs may get jealous and reject the puppy and give a the dogs equal amounts of attention I know this is hard because when you see the pup your probably gonna want to drop to your knees and cuddle it lol hope everything goes well :) x