Battle tactics
The Vikings did not really have very good tactics, although the people which fought together were like family to each other. These bonds are what made it so that they didn't need a phalanx or a strategy. Their type of warfare was best at sea, with their aerodynamic ships, 50 Vikings rowing the boat and a huge sail.
Training
The Viking children began training at a young age. They would start out by practicing sports, hunting and raiding. These factors would make them into good vikings.
Weaponry
The Vikings had a very good armory with very strong steel and bronze. They also loved their swords so much that they named them and were buried with them. The Vikings helmets having horns is a myth, they would have metal feathers on the sides of their helmets to look fierce in battle.
Ships
The vikings are known for their longships with shields on the sides and a wooden dragon on the front. They were a lot more than just that, they were aerodynamic, sleek and fast. The vikings made them thin and pointed at each end of the ship and fifty vikings rowing the ship and a giant sail. The Vikings had the dragon on the front to scare enemies.