Buying Strategies
Complete property sets are very lucrative because they allow you to build houses and hotels on them and charge much higher rents. Therefore, you should always buy properties that have all of the squares available so that you have a chance to complete the set. You should also buy any property that prevents an opponent from completing a property set. Railroads, as a set, are landed on more frequently than most other properties. Two or more railroads in the early to mid-game can provide steady income. However, their value diminishes in the late game when properties with houses and hotels eclipse their earning power.
Probability
On average, the properties between the "Go to Jail" square and the "Jail" square are landed on more frequently than the properties on the other half of the board. This is because players are sent back to the "Jail" square when they land on "Go to Jail" or draw a card that sends them to jail. In his study of Monopoly probability, Truman Collins found "Illinois Avenue" to be the most frequently landed on property, although he concluded that the orange block was the most lucrative color set because of its cheaper purchase price versus the red and yellow blocks, and higher earning potential versus the light purple block.
Jail
Sitting in jail can be a good or bad tactic depending on the context of the game. At the beginning of the game, the smartest policy is to get out of jail as soon as possible so that you can buy up property before the other players. However, once the property is bought up on the board and especially after houses and hotels are built, the trick is to stay in jail as long as possible to avoid paying rent for up to three turns.
Building
On every property, the third house gives a dramatic increase in rent, so the best policy is to build at least three houses on one of your property sets before spending money on other properties. The rent from this one property set will give you the funds for additional buildings. If you are stuck with a lot of low-value properties, it can be wise to buy four houses on each property to reduce the total number of houses available to other players.