Paladins often use Herald Of Zakarum - HOZ (+4 PC skills) or Exile (Life Tap/Defiance aura) made in a base with up to 45% All Res or 65% ED/1xx AR. Shields are responsible for Paladin's Smite damage and must be elite (or upgraded) to deal max dps. Note that all elite Pala shields provide +/- 1 the same damage and only the requirements and defense are different.
Block chance lowers each time you level up and it should be kept at 75% by investing points into Dex. Magic/white shields roll up to 4 sockets, unique/set 3 soc and rare 2 soc.