MOST IMPORTANT: Attach leashes/leads under the bike seat so that your hands are free. Do not attach leashes to the front of the bike!
MOST IMPORTANT: Leash length must be short enough to prevent dogs from getting in front of the bike. I use 4' leashes with collars and 3' leashes with harnesses.
Dogs must be large enough so that they cannot easily go between the bike wheels.
Keep dogs on the curb side of the bike (e.g. on the right side in the USA, and on the left side in Britain).
Go at the dog's pace. Do not force them except in a brief situations like clearing an intersection. Dismount and walk your bike if they get too hot or tired.
Be prepared to suddenly stop. Some dogs can suddenly stop to poo.
Be prepared to suddenly lean/shift your weight. Dogs can lunge at tasty litter or cats hiding under parked vehicles. Dogs pulling away from the bike (perpendicular) will cause the bike to turn in that direction; the slower you're moving, the sharper the turn and the more you will need to lean in the opposite direction to make up for it.
Turning in the direction away from the dogs is easy; they have no choice but to be pulled along. Turning in the direction towards the dogs, move your knee out so as to pull the dog back and away from the front wheel.
Bike parking and walking:
Practice parking your bike with one dog attached. Remove or tuck away any breakable items like mirrors. Tell them to stay, and then walk away from them. Allow them pull the bike over if they do not stay. They do not like the bike crashing to the ground or on top of them, so after a few crashes they should learn to not pull over the bike. You will eventually be able to leave them with the bike unattended.
When walking your bike and dogs, be prepared to let go of the bike and let it crash if they tug away too hard, otherwise they will pull you over on top of your crashing bike.
At first, the dogs will vie for lead. They will eventually settle into positions.
You will occasionally need to untangle the leashes. Less so after the dogs settle into positions.
Beware that if one dog suddenly stops, the other could keep going, and front braking can cause your rear tire to flip up off the ground.
Good luck and skill! And of course wear a helmet!
For questions or suggestions, contact Thor/Torsten Pihl at thorgolucky.com.