[thejeff]

The sieging/storming mechanics are pretty simplified.

You can't storm until the wall has been breached. Which essentially means the gate is down and there is a way in. The size of the entry depends on the fort you're storming.

What you want once you attack depends on your strategy. Archers are at a penalty trying to shoot anyone behind the walls, but I've had luck holding back and letting his troops come out to attack me. If he has mostly mages and archers then you really want fast melee troops to get in and reach them.