Strategy of monopoly

I didn't see a very basic strategy
on the How to Win at Monopoly
page. The second monopoly on
each side of the board always
has a better return on
investment. The houses cost the
same as the first monopoly but
the rents are higher.
The oranges are highly sought
after because of their
relationship to the jail square.
Two of the oranges are 6 and 8
away from jail, certainly
common dice rolls. Also, if
someone is looking to get out
free with doubles then you have
taken 2 of the 6 doubles away.
The dark blues have the best
return on investment in the
game. They are expensive but
are a far better deal than the
greens. Remember, you have to
build evenly. Since there are
only 2 properties in the dark
blues, $2000 gets you to hotels
on both. Those 3 greens are
going to soak you for $2800 to
get to 2 hotels