Based on this website, the rewards are as follows:
Action | Frequency | Reward
Catch Pokemon | First time a day | 500 XP and 600 Stardust
Catch Pokemon | 7th consecutive day | 2,000 XP and 2,400 Stardust
Spin Pokestop | First time a day | 500 XP and “additional items”
Spin Pokestop | 7th consecutive day | 2,000 XP and more “additional items”
It should be noted that the 7th consecutive day bonus is called a 'Streak Bonus' and is in addition to the First time a day bonus. See below for a screencapture of a streak bonus that includes the first catch bonus.
It should be noted also that the 7th consecutive spin gives more items and according to an official PokemonGo update on March 21st, a guaranteed Evolution item.