Where did people learn to play Heroes?

The first time I encountered the game was at a friend's house (Heroes of Might and Magic III). He explained the basics, but I didn't really like it at first. Later, I learned how to play, and I played the third installment at my friend's house until I installed it on my own computer. But soon, friends recommended the fourth game. A friend let me play, and I liked it more than the third. I played it for a long time. Then, I got to play the fifth game. I played it, but couldn't finish it, so I gave up. A couple of years later, I tried again – I completed both expansions, but got stuck on the main part, on the campaign for the elves. When the sixth game came out, I bought it, but it wouldn't install. So I never played it. But out of all the games, the fourth remains my favorite.