The Daily Reward is received by an email from Zynga. Once a day you can choose Energy, Materials or Mystery. Energy will give you one randomly chosen amount. Materials will give you a build item you need or a Bonus Crew. Mystery is random, but includes minor items that are no longer available. You only get to pick one of the 3 choices.
If you're not getting the emails, try this: on Facebook - Click the arrow in the upper right corner of your homepage. Choose Account Settings. On the left choose Notifications. Scroll all the way to the bottom and choose Other Applications. Place a check-mark on the CityVille row. It's uncertain if this works for everyone.
