Hi,
This is a good bug for all clases to get much hp/mana/and all stats.
This is how to do: First go to the spirit healer outside shattrath.
Get your gear red(best thing is to get on ur flying mount fly high fall and die then take ress sickness) now empty your backpack (starting bag) Put following items in the backpack (the red items that u have equipped) :Main hand, offhand, head, shoulder, chest, bracers, hands, waist, legs, boots. (If u dont have an offhand just skip that). Go to nearest repair. (Dont forget repair bill). Repair when the items are in the bag! Now you will get the stats that u have with the gear equiped. Put ur gear on and the stats will stack. can be done many times.
PS:Only tried on hswow private server (Hacking Source WoW)
I enjoyed this very much with a rogue. (95% crit, 95% dodge, 80k hp)