Is there a ring of golem control in the D'Arnise Keep somewhere?? I read a post that mentioned it but I can't seem to find it.

Yes, it's actually the ring of earth control. It's in the same place you get the blue flail head; the lion statue in the room beyond the castle's forge.

I've got that and when I tried to use it on any of the golems, I get the message that the golem saved vs spell no matter how many times I try it. How do I use it to charm or control a golem?

Its a Ring of Elemental control if you looked at it properly...
It works on ELEMENTALS not Golems

Patriarch, the ring of earth control has a loophole. You can use it on golems, as well, provided they fail their saving throw, just as an elemental would have to.

A tip:- There are many really great spells which involve a saving throw negating the effect. So to use these effectively use greater malison, doom, etc. before casting pet golems are really easy this way.

With magic resistance lower resistance first or simultaniously(sp)with the above.

Bonus tip - If you didn't know you get all exps earned by charmed/dominated/summonned creatures just not the kill numbers or names (like that mattered) - Curdis