I'm playing a mage. I posted this link earlier, if you have the game sign up for a free account and link your own profile. As long as you play online, it will update your progress there

JKTrix's Player Profile | BioWare Social Network

Combat is the basic 'click a target, click a skill, let it rip'. The strategy stems from that. If you played FF12 you would be familiar with it (if you never played something like Neverwinter Nights before). You can pause whenever you like to think about your next step, which is probably going to be required more often than not. The Tactics ('Gambits') are okay, but you will want to micromanage your troops if you want to keep everyone alive. Some of the battles can be pretty rough, and if you take your eyes off of one of your teammates for one second they can probably die.

The position of your party members seems pretty important too. You can tell them to go somewhere and stay there, doing something until you tell them otherwise. Useful when you want your archers to stay perched in one spot, mages in another spot and let your melee guy go in and smash things. Particularly when you come up against enemies who can damage multiple people in one hit, having all your guys bunched up together is a bad idea.

The battle I'm taking part in now, the staff my mage has has zero effect on the enemy, and I had just sold my other staff prior to that. So he's stuck with just his spells, which drain his MP pretty quick while my archer, other mage and weak knight do the bulk of the damage. I like that you recover your HP and MP periodically when you are not 'engaged', but more often than not when you're fighting waves of enemies, the next wave will engage you before you can even start regenerating.

I find myself taking Morrigan out of my party when I plan to go persuade someone to do good stuff. Her approval rating drops quick.