The icons on your homescreen can be handled as follows:
Adding to homescreen:
On your home-screen, click the menu hard button (the one with three lines on it) then click "add". You will then be given the choice of shortcuts,widgets,folders or wallpapers. Click whichever one you wish to add, then you're done.
You can also add application shortcuts from the "app drawer" - drag up the drawer from the bottom of your screen, then click and hold the relevant app icon. It will then be automatically added to your home-screen.
Organizing Icons:
When on the home-screen, click and hold an icon. It will "float" and you can then drag it to whatever position you want on the screen. Simply release it when it is placed where required. Note that the scroll will automatically align them into a grid. If you drag it too far to the left or right it will look like its disappeared - it hasn't - there are three home screens. Simply flick the screen to the left or right and you will see the icon. Flick it back to replace it.
Deleting Icons:
To delete an icon, click and hold it and it will float, whilst stick holding your finger on it, drag it down to the grey app drawer icon at the bottom of the screen. The grey icon will turn red and a recycle bin icon will appear on it. Drag the icon onto the bin and it will disappear.