Get used to the Google experience. Because the google bundle services is tied into your google account you'll find using the calander/mail/IM/voice will make your experience a very good one. Look at some of the apps other people are downloading and giving good reviews. Youtube is your friend so google some tips on how to optimize your android device. There are TONS of informational videos on the web for you. I learn much better when I see it.
Customizing is up to you so play with it and set it up the way you feel is best. If you don't like some of the widgets on the stock screens just touch and hold then drag to the bottom until you see the the red trash can, then let go, it's gone. If you want some icon to place on the home screen bring up the menu where the icons are and press and hold then you can move the icon around until it's where you want it.
Late