Words with the "ou" spelling:
* House
* Mouse
* Out
* About
* Shout
* Cloud
* Count
* Hound
* Proud
* Vow
* Bow (as in a bow and arrow)
Words with other spellings:
* Now
* How
* Cow
* Town
* Brown
* Down
* Crown
* Flower
* Power
* Hour
* Sower (one who plants seeds)
Note: There are also some words with "ow" spelling that have the short "o" sound (like "box" or "fox"), so be sure to pay attention to the context.
This is not an exhaustive list, but it gives you a good starting point.