Dog training motivation

Question
I'm not sure if this is the right section, but my questions pertain to motivating my dogs during training so I hope it is. :)

We rescued my dogs, Edgar and Ellie, from a farm when they were puppies, and they are about 3 years old now, and we've never seriously trained them. They know the basic commands, like sit and lay, but I would love to teach them how to walk with me and not to jump on everyone when they see them. They are pretty big dogs, Great Pyrenees, Saint Bernard, and some other dogs mixed in.

I'm not quite sure how to motivate them though. Neither one of them have ever played with toys, even when they were puppies. We've tried Frisbees, balls, ropes, nothing. I don't know how to motivate them other than treats, and I want to be able to play with them but they just don't play. They act like they want to play with us, but they completely ignore toys and just stare at us. Are they just not into toys? Or are there some other toys I could possibly try and see if they like?

I have no problem motivating them to behave well with treats, but Ellie, my girl, is very treat picky. She doesn't even like half the treats I give her, and when we finally do find treats she likes, she gets tired of them very quickly.

So to sum up my questions, I would love to play with my dogs, how can I get them to play with toys? Or what other toys should I try? And how should I reward my picky eater? Are there any other means I could reward them?

Answer
Reinforcements, by definition, are something the dog wants.  So, don't be hesitant to use food to motivate your dogs if they like treats.  I actually use real meat, or home made "liver brownies" when I train my dogs on a difficult or new behavior.  The key is to use food properly.  Good reference site on how to train using clicker training: http://www.clickerlessons.com If a dog doesn't have a long attention span, or tires of the treats quickly, then keep the training sessions short, but do several during the course of a day.  Also, train each dog separately, just in case there's some signaling going on between them that is preventing one dog from feeling comfortable enough to eat. Anxiety will stop a dog's appetite faster than anything.
Some dogs are just not interested in toys.  I have one like that, and yet she has an Intermediate Tricks Title and is a registered therapy dog.  She was motivated by food, but also by "privileges" or life rewards.  So, for example, if she wanted to out, I asked her to "sit" to get me to open the door!  The door being opened thus becomes her reward for the sit. Sometimes, the reason that dogs don't play with toys is that they had no experience with toys as young puppies.  Pups have a window of opportunity, the optimal socialization period, which ends when they are about 4 months old.  It's during that time that exposure to toys usually leads to having an adult dog that will play with them.  But, there are certainly other ways to enjoy your dogs.  Most dogs can do K9 nose work, tricks, or rally obedience.  You may want to experiment to see what foods your dog chooses: cheese, turkey, chicken, beef, etc.  Some dogs have very definite preferences!