Combat while Mounted
With a DC 5 Ride check, you can guide your mount with your knees so as to use both hands to attack or defend yourself. This is a free action.When you attack a creature smaller than your mount that is on foot, you get the +1 bonus on melee attacks for being on higher ground. If your mount moves more than 5 feet, you can only make a single melee attack. Essentially, you have to wait until the mount gets to your enemy before attacking, so you can’t make a full attack. Even at your mount’s full speed, you don’t take any penalty on melee attacks while mounted.
If your mount charges, you also take the AC penalty associated with a charge. If you make an attack at the end of the charge, you receive the bonus gained from the charge. When charging on horseback, you deal double damage with a lance.
You can use ranged weapons while your mount is taking a double move, but at a -4 penalty on the attack roll. You can use ranged weapons while your mount is running (quadruple speed), at a -8 penalty. In either case, you make the attack roll when your mount has completed half its movement. You can make a full attack with a ranged weapon while your mount is moving. Likewise, you can take move actions normally
And
Ride (Dex)
Check
Fight with Warhorse
If you direct your war-trained mount to attack in battle, you can still make your own attack or attacks normally. This usage is a free action.
The ride DC 10, otherwise the mount attacks, but the rider can't.
However does this mean the paladin on his turn could full attack and then the mount could move (for its turn)? This effectively moves the paladin from combat after he full attacks...
No, I don't think that's possible.
Horses in Combat
Your mount acts on your initiative count as you direct it. You move at its speed, but the mount uses its action to move.
Combat while Mounted
If your mount moves more than 5 feet, you can only make a single melee attack.
ok thanks ... next question then...
Could the mount charge as its action and trample someone (trample feat).. and the Paladin use the charge to attack with a lance for his action?
Well to use the trample, you have to be doing an overrun. You can't charge as part of an overrun, thus you can't charge as part of a trample. I believe the rider could make an attack if he made the appropriate ride check.
This maybe a technical reading, but I think the rider and the mount would still draw AoOs (the defender's choice if he can only take one).