Core Skills For All Pilots - train them all to 5 The time invested will be repaid many times over throughout your Eve career.

Engineering - To maximize the power core.
Electronics - To maximize the CPU.
Energy Management - To maximize the capacitor capacity.
Energy Systems Operation - To maximize the rate at which the capacitor recharges.
Energy Grid Upgrades - To reduce CPU requirements.

Stacking penalties
1 - 100%
2 - 86.912%
3 - 57.104%
4 - 28.247%
5 - 10.59%

Hardeners to use
Angel - All
Amarr Navy - EM/Thermal
Blood Raiders - EM/Thermal
Caldary navy - Kinetic/Thermal
Gurista, Mordus, Gallente - Kinetic/Thermal
Khanid - EM/Thermal
Mercenary - EM/Thermal/ (Kinetic missiles)
Mordus - Kinetic/thermal
Odamian - Kin/therm
Rogue Pirate - EM/Explosive/Kinetic
Sansha - EM/Thermal
Serpentis - Kinetic/Thermal
Zazzmatazz - all types of damage

Standings to use agents
Lvl 2 - 1.0
Lvl 3 - 3.0
Lvl 4 - 5.0
Lvl 5 - 7.0