Is it best to chainsaw all the side branches off of larger branches before running through a "wood chipper"?

It is best to ask the guy at the rental company how thick a branch the chipper can handle. They usually have a funnel that you feed the branches into and as a rule,if it will go through the funnel the machine should be able to chip it ok. Side shoots often make the stuff too wide to go through the chute but if you cut it all too small unnecessarily,you will have wasted your time. My advice is to wait for the chipper to arrive and see what it can handle size wise. Then have one person feeding the chipper and one person going through the stuff to cut up the bigger pieces.