Where did people learn to play Heroes?

About 5 years ago, when I just bought a computer, a friend gave me a few disks to install, and among them was Heroes of Might and Magic III: Armageddon's Blade. I installed it, launched it, and... didn't understand anything =). What attracted me was the huge number of different creatures, and it was interesting to find out who was the strongest and who I didn't need to be afraid of. At first, I lost EVERY time, until that same friend came over and showed me what and how to do. That's when I got hooked.