I am getting a Lab puppy in the near future, possibly from working stock, I would like to teach it to retrieve a dummy.
Obviously you wouldn't want a dog chewing the dummy. So are there any type of toys that i should not buy, I was thinking about squeaky ones?

The vote is split on squeaky toys but the general opinion is that they are a big No. I personally don't let my dog have them. They may encourage a dog to bite down harder to make it squeak. If you intend to work your dog you don't want him picking up game and then biting it hard to see if it squeaks. It could encourage hard mouth. Also never try to pull anything from the pup's mouth. And never tell him off for picking things up. It follows that tug of war games are frowned upon as they too can encourage the dog to grip harder. If you intend to teach your pup to retrieve you can start with a knotted sock or tea towel or anything the pup will pick up. Doesn't have to be a dummy. Let the pup chase after it and when he picks it up encourage him back to you for lots of fuss and praise. A retrieve is just a recall with the dog carrying something, so work on that first before trying to formalise it.