On the Apps page, you can control both what apps are synced to your iPhone and also the arrangement of those apps on the iPhone's screen.
On the left side of the screen are all the apps that you've downloaded to your computer's hard drive. Click the Install button to the left of an app to sync it to your iPhone. You can sort the list of apps by name, kind, category, date, and size. Check the Automatically sync new apps box if you want newly downloaded apps to always be synced.
On the right side of the screen, you'll see the homescreen of your iPhone and the apps you have on it. Here, you can arrange apps and make folders prior to syncing.
- Add/Remove Apps - If you checked the box next to the app on the left, it will be synced. You can also add an app by dragging its icon from the left box onto the screen on the right. To remove an app from your iPhone, mouseover it and click the X that appears.
- Arrange Apps - To arrange apps on the screens, drag the app icon to where you want it. To move an app to another screen, drag it to the screen you want it on in the far-right column.
- Make/Delete Folders - To make or delete folders on this screen, follow the standard process for doing this.
- Add/Remove Screens - To add another screen of apps, drag an app to the last screen in the list on the far right (the gray one). The remove a screen, simply drag all apps off it to other screens.
Some apps will share files between the iPhone and your computer. This box is where you manage those files. Click on the app you want and either add new files from your computer to the iPhone or save files from the app to your computer.