You can get reward points in three ways (on Mafia Wars).
1) Pay for them. There are eight different methods and these can be found at the bottom of the Godfather page.
2) Levelling. Every two levels on Mafia Wars you earn a reward point.
3) The Daily Chance. If you win the daily chance you can win a maximum of 1000 Reward points (have a look each week for the amount). However if you collect the free ticket that Zynga give you every day and collect 6 in total you can collect a ticket mastery bonus. If you get to Level 6 then you are rewarded with up to 5 reward points.