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!\
Check out this area of the forum for your unlocking questions: Cell Unlocking
Posted from my CrackBerry at wapforums.crackberry.com