Units to Know

N= (kg*m)/sec^2
J= N*m
V= (N*m)/C
E-field= N/C
Capacitance= C/V

That's really all you need since everything else can derived from equations or vice versa.
I.e. V=E*d
Or, for your example
Power = Energy/time= J/s= (N*m)/s

 

Honestly, I never really had to learn any of these. I think that by working with these long enough it sort of just becomes second nature.

 

yup, it has to become second nature to you. memorizing them is useless.

 

1 second = 1 ohm farad

I use that once or twice a year to wow my audience.

 

Oh, and intensity is kg/s^3.

As in, if you have a situation where you suddenly have 1 kg of material after 1 second, then a second later you have 8 kg, and a second after that you have 27 kg, etc. you have an intensity of 1.