Ok, attempting to bring this out of RnF. I'll try to keep this easily readable.
There's basically 6 types of hate procs.
1) Straight up hate procs. These are procs like Enraging Blow that are straight up Hate. These give a hate value equal to what the effect says. So, if a spell increases hate by 500, each proc is 500 hate.
2) Direct Damage. These give hate equal to 1:1 for the damage. So a proc for 175 damage gives 175 hate.
3) [Proc] Stuns. The approximate hate value for a stun component is 400 hate. So, a proc with even a 0.1 second stun gives 400 hate.
4) Runes. These give hate for mobs with aggro on you in a 2:1 ratio. So, a rune proc for 100 damage will increase hate by 200 on all mobs currently aggroed to you.
5) Debuffs. This is an umbrella category where the individual procs will vary greatly. In terms of weapon procs, you could lump snares, slows, and AC debuffs into this category. For PoP, theres not a ton of weapons that fall into this category. It's basically Vanazir and that's it. Jagged Onyx Staff in GoD brings Frostbite. Frostbite was around 560 hate per proc. Vanazir was around 700-800 hate per proc.
6) Poison/Disease counters. Not hugely relevant in PoP either. Fist of Bertoxx is all I can think of.
These all combine in an additive fashion. So, a proc like Anger (Dark Blade of the Warlord) which looks like this:
1: Stun (1.00 sec/68)
2: Decrease Hitpoints by 100
3: Increase Hate by 650
Would be 400 + 100 + 650 = 1150 hate.
Proc rates are pretty easy to look up on lucy. In the PoP era, you'd basically be looking at DBotW and Bloodfrenzy being ridiculously strong. Combat Effects and AAs like weapon affinity will increase procs per minute. Dexterity does this as well, but that goes without saying.
Hate from melee is more or less DMG + DMG Bonus per swing attempted (hit or miss doesnt matter).
Mods like Echo of Anger (found on the PoP class BP and far more commonly on the GoD gauntlets) multiply all hate. The SK Voice line does the same.
Some good reads if you have the time:
http://giline.versus.jp/shiden/stun_e.htm
http://giline.versus.jp/shiden/melee_e.htm