progressing really well in training now on to heavy stuff....
trying to teach my rescued staff to "hold" an object then "give" to me....using a dumbell for training only.
Buddy not even interested in it just the treats....looks at me as if to say what do you want me to do...with glances towards the treat bag!!
question to start with do i physically place the dumbell in his mouth ask him to hold then give initially just for seconds and reward when he does it?
this is going to eventually progress to dog sitting beside me throw the dumbell dog retrieve it and present it to me and then give it to me..
help!!

I do not know if you are familiar with clicker training but this is a short overview of the process for retrieve (it is not the ONLY one, but it is tried and tested by the best)!

Sit in chair
Dog in the "present" position
Hold retrieve item in one hand
Shape by clicking and treating the following incremental steps: 

Look at dumbbell
  Sniff dumbbell
Touch w/nose
Touch with mouth/teeth
Put mouth over bar
Close mouth over bar
Hold in closed mouth
Increase hold duration

Ie click and throw treat away so the dog has to stop the behaviour and return and repeat.

Once that is good, hold dumbbell out to right and left of you, then place on chair, then on floor to generalize.

Then add distance
Finally add throwing

hadnt thought of using clicker to teach this..i presume it is possible to do away with clicker once taught..
not sure i could use clicker in training class though...
any other suggestions.
question how do i get him interested in the dumbell as he tends to focus on the treat or the hand that gives the treat...confused

The beauty of a clicker is that the dog makes such a strong association of "click = there's a treat coming!" that you can actually keep the treats somewhere else - say, on a shelf nearby - and then when you click, the dog knows to stop the behaviour because he's done what you want, and he'll get a treat.  Then you can walk over to them and give him one, and he'll be much more focused on the task instead of the food.  I have to do it on the odd occasion I work with my brother's dog - she's a 'take-your-fingers-off" kind of dog, and is focused on food in training to the point of obsession, and total inability to work.  But with the clicker, I can get her to use her brain without losing digits!

Hi
If your dog is food focussed you're more than 50% there with clicker training.  Look at the 'Learning about dogs' website to learn about loading the clicker in order to get your dog motivated in order to initiate the learning process that Tohme is describing.  That way he will begin to problem solve and find the dumb bell interesting and rewarding as part of a free-shaping exercise.