For
each initial colony " base", farm, and 100% food bonus you should build one entertainment building.
Your homeworld's capital produces twice as much food so build two entertainment buildings for it. This will seem like many tiles being used but a huge, happy population per planet equals huge amounts of cash,influence,security from "light" invasions,soldiers for transports, and colonists for colony ships or transports.
You can ferry population between you're planets.If a planet is at maximum population then launch a tranport or colony ship and ferry them to a developing planet; and then send it back to get more colonists.When you launch it from the developing planet set the number of passengers to "1" (one million), 0 will not work.
-Wade