Is there a place to find detailed information about Dual Wield? For instance, is fast main hand slow/hard hitting offhand best?

It swings at whatever speed the weapons are. Check the auto attack tooltip and it explains quite a bit. Fast weapons tend to help with leech effects while slow weapons are probably better at doing damage. I will confirm that auto attack damage is calculated totally differently from skills. The damage is calculated directly from the weapon's damage. This is not the case with melee skills where delay is taken into consideration. If you are focusing on skills that utilize a lot of auto attack damage, a high damage weapon might be a good idea.

So the tooltip says I have roughly 25% chance to dual wield. What I'm curious about is how the second weapon is affected. I'm playing Warrior so I have a lot of weapon choices to pick from. The thing is if it behaves like some games (EQ for example) it's just a set percent chance that the second hand will go off on a main hand hit, so that would mean I want a fast mainhand and a slow offhand. But if it behaves like other games (Diablo) it would take both weapons into account and dual wielding a "poor" weapon would actually lower my DPS.

When dual wielding the weapons operate on independent timers. So if your primary weapon is swinging every 3 seconds, it will check if you are able to auto attack every 3 seconds (not casting, not dead, not stunned, not feared, have a valid target, etc). If you have a valid target it swings and the interval resets. This is pretty transparent now that the primary auto attack timer is visible. Dual wielding works the same way except that it also has to check and see if dual wielding succeeded, too.

If I recall correctly, skills only take the primary weapon's damage/delay into consideration. So your off-hand weapon only affects your dual wield damage. Dual wielding a rusty dagger will not break your DPS. I'm pretty sure that's how it works, but I'd have to double check to verify that.

Thank you for the quick replies. I appreciate it

So high dmg main hand for skills, and fast off hand to trigger dual wield checks more often.