Resource giving building

[SarChasm]

I'm trying to make a building that gives X amount of gold/lumber per second when you stand within a certain radius of it. No clue how even start though, can anyone help?

 

[Doom-Angel]

Event - Timer - Every 1.00 Second
Action - Pick every unit within 500 of (Position of Building) and do:
Give 1 Gold to (Owner of (Picked unit))

simple one