Paladin Tips

Tips

Use Hammer of Justice to interrupt spell casters from using their spells. Make sure another player does not stun the monster before using Hammer of Justice (so you won't waste it).
Ask players in the party which Blessings they want (if they know the Blessings). Ask party members to tell you when the Blessings wear off.
If another Paladin joins the party, work out between you which auras and Blessings you will use.
If a monster is attacking a weak party member like a caster, stun the monster with Hammer of Justice.
Getting away (extreme)
First start running. Right before you die, use Divine Shield. Now continue to run. Cast Lay on Hands if you need it. With these abilities you can run away for quite a distance even with a lot of monsters attacking you.

Equipment
Focus on items that give stamina and defense. You can go for a sword or blunt weapon and a shield, or a two-handed sword or mace. You might want to train up all of these abilities so you can pick and choose which to use based on what weapons you have available.

Two-Handed Weapons vs. Shield and One-Handed Weapons
Both are great. A two-handed weapon is good against monsters with a lot of armor. A one-handed weapon is better against monsters you wish to interrupt and against monsters with less armor. You might want to train both up and switch between them.

Summon War Horse
Paladins can get their own custom armored Warhorse via a quest at level 40 and level 60. Paladin Epic Mount quest: To begin, talk to the paladin trainers Duthroian Rall or Brandur Ironhammer. Paladins who have completed their Epic Mount quest can repeat the final event in Scholomance for fun (and loot) by speaking with Lord Grayson Shadowbreaker.

Profession Options
You can pick whatever you want. You might find these more tailored to the Paladin:

Mining and Blacksmithing - Paladins can create their own armor. This is a popular choice with Paladins.
Mining and Engineering - Paladins can create range weapons and special engineering items.
Enchanting - Paladins can enchant their equipment to make themselves more powerful.
Herbalism and Alchemy - Paladins can create buff potions or healing potions.