Got a blackberry from work. Before I was adament in not getting one, but since they decided to throw a digital leash on me I have no choice. But I've conformed, its pretty slick.
Hopefully this place will answer all my questions with this phone.
Check out the BlackBerry 101 How-To Lecture Series ! This will help you with the basics such as downloading apps, themes, wallpaper, ringtones. It's also a good idea to browse the forums and read as much as possible. Many questions you have are answered there already!