I'm providing this alternate link to pandamancer's earlier link to Sisiutil's Beginner's Guide:
Sis's
The above links to his thread in the Strategy Articles subforum (to this forum) and contains a more current version of the guide than the one in the War Academy.
Sis's guide is a fairly comprehensive beginner's guide that pretty much covers all major topics that a new player should be aware of. I think it is a very good place to start to get accustom to the game. There are other very good articles in the sub-forum that you can tackle later.
Civ IV is a very complex game. Much more so that Civ V. It will take time. However, following that guide should get you winning in due time on mid-levels like Noble, Prince and maybe Monarch. It should be noted that some of the tips/strategies covered in the guide don't necessarily translate to higher levels of the game which require more advanced concepts.
With all that said, and I do encourage you to read that guide, you can learn much about the game by spending time on this forum playing games with others and getting advice as you play. It's really the best place to learn. Let's Plays are also very helpful, if you watch the right ones.
I would also recommend that you play BTS and get the BUG mod or BAT mod.
I'd also advise that while it is good to learn about traits and stuff related to leaders/civs, I would focus less and that and more on the mechanics of the game. Ultimately you don't win this game because of leader traits and unique units, but rather how you master certain mechanics and strategies, especially in the early game. What do you build first in a city? When to start first settler? Trade routes? Importance of Workers and Granaries? Empire management and city specialization? What to build and not to build in cities? Great People generation and usage?
(note: there are a few good guides and general references in the War Academy. Many articles are a bit outdated. Ones related to some specific victory conditions are quite good, like Jesusin's culture guide. Later on, you might delve into guides related to Corporations)