Ok
First, the most important for any dpser, hit cap
a person with one 1h weapon or one 2h weapon need 8% hit to not miss the RAID BOSS, same for ranged weapons, 27% for dual-wield and 17% for casters
Those numbers are total, aka talents + gear + raid buffs, you don’t have to have 17% hit from gear only for a caster for example, that would be sacrificing a lot of stats
The % is lower in heroics as bosses there are lower in level than the raid bosses
No, increasing hit beyond those numbers is not beneficial, you just need those numbers to not miss, any more is redundant and a waste
http://www.wowwiki.com/Hit
For expertise, this is second most important for melee
You aim for 26 expertise, which is 6.5% for raid bosses, that is 214 expertise rating, you can get some expertise from talents though, don’t need to get it all from gear. you should only aim for 6.5% the soft cap to cancel any dodge, same idea with hit, the hard cap is 14% expertise, which will allow you to avoid any parrying too, but that is a waste as you can avoid boss' parrying if you hit the raid boss from behind
You only need 22 expertise for heroics as bosses there are lower in level than raid bosses
http://www.wowwiki.com/Expertise
Third, critical strike
It is the % chance of your attacks to do more damage
for example, you hit 100 hits, each hit do 100 damage, if you have 30% crit, then you will have 70 hits with 100 damage, 30 hits with 150 damage
same idea for a healer, but with heals isntead of damage. some classes need a lot of crit, like disc priests compared to holy priests
death knights for example should reach 30% crit easily self buffed with epic gear
http://www.wowwiki.com/Critical
Fourth, haste
Anyone who think haste is useless at this point of time, is simply a noob, specially as its benefit going to be greater in the next expansion
"In World of Warcraft: Cataclysm, haste will also increase the rate at which you gain energy, runes, and focus. Retribution paladins and Enhancement shaman will have a talent that allows them to take advantage of this benefit "
with haste, you decrease global cool down, which means you can use more spells/abilities faster, of course if they are not under their own respective cool downs, global cool down is 1.5 sec as far as i remember, max possible is to lower it to 1 sec
haste reduces the time you need to attack or cast a spell, in other words, it takes you less time to land the attack or the spell than before, instead of needing 3 sec to finish casting a spell, you might need 2.7 sec for example, same with auto attacks, the time needed is lowered the more haste you have
haste is considered double edged weapon for casters though, the more haste you have, the more spells you can cast, your dps/healing output increases, BUT your mana usage is going to increase too, which means the more haste you have, the faster you will run out of mana. So first, make sure you won’t run out of mana, your other stats are balanced according to what you need, and most important make sure haste actually benefit you, then you can increase it. Some classes simply don’t need haste, not sure which classes though, need experts to comment on this
a simple example is holy paladins, their healing will increase big time if they have a lot of haste, some have ~900 haste, some have even more, but if they don’t have the right gear, they will run out of mana really fast with spamming healing spells on tanks
http://www.wowwiki.com/Haste
Armor penetration
This stat simply makes your attack ignore a % of the boss’s armor, when the armor is decreased, your attacks will do more damage
Imagine a warrior tank with 10k armor, and another with 5k armor, the one with less armor will take more damage, it’s the same idea vs. bosses. Once you have enough of the other stats, you can increase this one, don’t ignore other stats and go directly for armor penetration. If your attacks are weak, as in low AP, then armor pen won’t benefit you much
Armor pen going to be canceled next expansion, they will change it somehow
http://www.wowwiki.com/Armor_penetration
Spell Penetration…. pvp stuff, I don’t care about pvp, so don’t have much info about it. If you only care about pve, ignore it
Don’t waste gem sockets for stuff that can “help” you while it doesn’t maximize the benefit you can get from the socket itself
For example, a death knight, doesn’t have hit capped, we don’t care about anything else at this point, you gem for hit, as if your hit is not capped, your damage is going to suffer big time
Let’s say a death knight has hit capped, expertise soft capped (26 expertise), has some haste and armor penetration from gear, what should he socket?
Simple, strength. Why? Because all the people who spent time and made god knows how many calculations reached the conclusion that if you got balanced DK, you will gain more from socketting strength than anything else
That can be different for other dps classes or healers, each spec has things that boost it more than others and might benefit more from a mixed gemming
Such statements can change as blizz change the mechanics of the game though, so need to keep updated
hopefully i didn't forget anything and didn't write anything wrong
^^
