Working Pups in Training !!
Team Work 
Learning to work as a team
Ruger leads
Working Together 
Their first trip to the mountains 
they do have harnesses on 

getting used to having something behind them
- empty box

Working and Training Pups
8 wks to 6 months old
quality time !! 
Puppies are in training from the day they go to their new home. Everything is a lesson ! 
If you don't want it to be a habit as an adult, stop it as a young pup !  

Step 1 
It is so important to socialize puppies outside the home and yard
Step 2 
Get them used to a leash, start using commands right away
Step 3
Get  a walking harness and a light rope/cable and connect a light empty box behind them about 5 ft or a little more and have them walk. It will make noise and bounce around. There is no weight to it - yet. 
Continue this in a variety of places until they get real comfortable with it. Little by little you can change the things they pull. An empty box, 2 liter pop bottle and work your way up to small log or something with a little drag to it. 

This is an awesome way to spend quality time and really build a bond with your pup.  
Some people will tell you do not work your pup before a year or some will say a year and a half.  Well, this is not working, it is bonding and training. There is a huge difference between pulling and empty box and learning words and pulling heavy weights. 

Once your pup has learned commands and is pulling light weights without problems, you can start to add weights very slowly. If your pup starts to get discouraged, it is too much. 
Adding a backpack.
 This is best to start around 6 months of age. If you have successfully done the above, a backpack will be just as easy as putting it on. Start with empty pack first. Then add something like newspaper to give bulk but not weight. Then after that, you can slowly add weights.