setbackground img for an iphone button

What you want could be easily done by placing UIButton instead of UIImage and changing its background image using method setBackgroundImage:forState: at TouchUpInside event handler.

multiple views in the tab
http://www.dirigodev.com/blog/post/iPhone-Application-Development-tab-bar-with-multiple-views-in-each-tab.aspx

woke up from the 3rd tab
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[[UIDevice currentDevice] setOrientation:UIInterfaceOrientationPortrait];
// Add the tab bar controller’s view to the window and display.
[window addSubview:tabBarController.view];
//Take this line this line and put it in your code.
tabBarController.selectedIndex = 2;

[window makeKeyAndVisible];

return YES;
}