Just a quick note for a check list of items you need for when your about to distribute your app to Apples App Store:

• Icon Image: Make sure your icon image is 57x57px in .png format.
• App Store Image: You need to have an image 512x512px image to be displayed on the app store. So a word of advice is to make any icon images as a vector so it can scale nicely to larger sizes for wherever you might need them.
• Screenshots: Screenshots of your app must be the screen dimensions of the iPhone, 320x480px(portrait)
• Distribution Certificate: Of course you need to sign the app correctly for distribution. This is fairly clearly explained on the iPhone provisional profile portal. Its very similar to setting up a developer provisioning profile.

Then its all about adding your application through iTunes Connect.