Here's a good guide to know what's good :
http://forums.d2jsp.org/topic.php?t=32190773&f=272Good guardian gear is max mana, heal mastery, intelligence, and enhanced effect on the armor, weapon, and heal charm.
Get a heal mastery weapon (intelligence, max mana, EE are bonus mods) get an enhanced effect chain (heal mastery, intelligence, max mana are bonus mods)
Get a heal mastery charm (intelligence, max mana are bonus mods) and get an enhanced effect heal charm.
Put your enhanced effect heal charm in the accessory slot. Bam.
Check the Market Place and LS trading for good guardian gear.
You'll find out what an MQ is at level 71

PM me with any further questions.