It's not hard but if you've never done any electrical work before PLEASE HIRE AN ELECTRICIAN.
The first thing you need to do is see if you have any open circuits in your circuit breaker box.
For instance the box above has 4 open circuits. I purposely use two separate circuits for water moving equipment. For instance, if the return pump is on Circuit A, then the powerheads, tunze streams, seio's, etc. would all be on Circuit B. So if one circuit blew while you are at work, you would still have water movement running. This is very important for keeping Dissolved Oxygen levels good until you get home.
Also, when I did my wiring I used AFCI (Arc Fault Circuit Interrupt) breakers and also GFCI outlets at the tank. On one circuit, I had 4 GFCI receptacles. On the other circuit, I had 2 GFCI receptacles.
Timers---
Intermatic Programmable Timer (Heavy Duty) [EI20C] - $49.95 : blackEnergy, The Power to Empower