To sell apps on Apples App store you need to enroll on their developer program and then submit your app to Apple for approval. (See links below)
Most likely yes.
There should be no reason to get free apps illegally. The App Store does not allow you to get an app illegally.
The official apple app store can be found at http://www.apple.com/iPhone/from-the-app-store/ . Beware of other sites that try to sell unlicensed apps or acquire your personal information.
Mainly from the App Store pre-installed on your iPad!
Apple's app store has over 250,000 apps. (See links below)
You can get new apps in the app store
The 'App Store' is for purchasing and downloading apps to your device.
When you go to the app store, there are many apps that are free. The app store has a list of highest rated/most often bought free apps.
No,the apple appstore has WAY more games and apps then the amazon app store
At the end of October 2010, there were more than 300,000 apps officially available in the App Store. See the link below for more information on the app store including a nice table of how many apps were in the app store at given dates
Nooks DO have an app store! its powered by the Android Store. it does not carry all of the same apps that the Apple Store does. and it carries apps that the apple store does not as well.
You can get apps from the Internet but they redirect you to the i tunes store.