At low levels, paladin tanking basically goes like this:
Have retribution aura up (all the time)
make sure righteous fury is up
Make sure blessing of might is still on
cast seal of righteousness
judge seal of righteousness
cast seal of righteousness
swing away
repeat on next mob
Try to get the rest of your group to keep from casting, swinging, whatever, until after you've at least hit the primary target once or twice. Also, try to get them all to focus on the primary target (the charms help a lot).
You can use Hammer of Justice to stop a mob in its tracks to judge righteousness again and hopefully pull aggro back or give the group time to kill it. You can cast blessing of protection on someone to prevent all melee damage to them (and usually send the mobs back to you), but note that this prevents the target from doing melee damage as well. Also, Righteous Defense will taunt up to three mobs attacking a friendly target. There are some good macros at wowwiki to help with this, but you can usually just use f(target your targets target) until you have the right person.
On longer fights (and later on when you can build aggro more quickly) start by judging crusader, the up front threat is less, but you'll do more over time).
Oh, and try not to use your bubble, this will result in any mobs on you scattering to the wind and likely killing the rest of the party.
Edited, May 7th 2007 5:18pm by nimrokon