To be effective in dual wielding requires quite a lot of investment and...I don't really see the benefits to be worth it.

Can any1 tell me how dual wielding acutally works?

Well a samy has criticals, so dual is very important to incrase the number of swings. Of you go for raw damage prefer a double hand weapon. But a samy is so nice when he slice your opponent in salami.

Dual throw for ninja is the same, you'll be amazed to see the effects!

How it works:
Simple you can hold 2 weapons at time and attack with them. The draw back is that your TACO and damage is lower. But with high level in dual you cancel the effects. And if you manage to get level 100 in the skill then you get a real killing machine without malus!

fighter can also dual wield, since they can berserk, they can deal damage much higher. just imagine doing 100++ damage on right hand and then 40++ damage on the other hand and imagine if you can have a few more swing in a round. that is lot's of damage!

Will I acutally see a dual wielding charc. swing twice?

yes..one right hand and then left hand. once you have put points on dual wield and their respecrtive combat skill high ( don't forget close combat too ). you can see them swing a lot of times.

And one or two of the available Secondary weapons are really nice. The way it shows up in combat, the weapon with higher initiative factor goes first, so if you've got a Bastard Sword and Diamond Eyes you would bash first, and a little later in the round you'll swing, or whatever. If you start right away with two, you'll build Dual faster than Close or any of the Weapon Skills. Plus, more swings per round, even if you miss, means building skills faster. Just switch to single weapon and shield when you're in a tough battle until you get around 30 in Dual.

Basically I think, especially on expert level, it is really tough early on in the game but ends up being worth it later in the game. You'll miss alot, especially if you dual two different classes of weapons, because your skills will be diluted between them and you'll have penalties on both until your dual skill gets up there. But I guess you also will peak later rather than sooner and do more damage in the long run.