The Diablo 2 Wiki archive is available for anyone looking for information on Diablo 2. All information here is pre-D2R but contains a lot of useful information that is still relevant. Updated sections for new D2R features can be found on the PureDiablo Diablo 2 section
Very good caster bonuses and some resistances. Although runes are not rare it's not so easy to use this unless you are Paladin since only few elite shields come with 4 sockets.