You probably have been reading reviews stating the lack of tutorial in the game. I honestly think it's best to set the AI to easy (Or normal if you're feeling risky) and get your hands dirty. It's the best way to pick things up. The game is extremely straight forward with a lot of depth. Hope you decide to buy it.

Seriously now, I can live without a tutorial, manual, whatever. But at least give me a description of every skill on every char, if only for reference. Purchasable and citadel upgrades, too.

I believe Arreat Summit was instrumental to Diablo2's success, so why not replicate it? Especially since Demigod requires significantly less pages anyway.

There is a wiki out there that anyone can contribute to (see here) but it is neither complete nor organized very well (IMHO).  The thing is that I want to be able to get a feel for the characters, or see the items side by side with the skills/upgrades so I can plan out my Demigod.  Granted, this can be accomplished from experimentation but it takes much longer.  I remember before WC3 came out Blizzard was constantly updating their guide (see here) and it helped to get a sense for what the heros did.

Maybe people who have the game could make a concentrated effort to update the wiki .  Either way, I think I am going to get this game I just wish that there was an official place to go and see an up to date skills/upgrades/items list.