Check back frequently to collect money from buildings, as otherwise you will find your fiscal situation get dire very quickly.
Paint
Paint has come a long way. I was painting the dining room of my girlfriend's parents last weekend, and it dried really fast. Three coats in a day fast, in fact. Perhaps consider finding out how long YOUR favourite brands of emulsion take to cease being wet by painting and then watching... you know what, you are smart. I will let you fill in the rest.
Raid quests
The Raid Quests are the easiest of the lot by far. Burn through these for money and valour.