I can't find a way to mouse over or right click Objects and their members and get more information on them than the members they contain (for objects) or the arguments they take (for methods). 

Coming from a java background whenever I have a question about anything in Sun's Java API, whether it be an object (like File, or SwingWorker), or a method (like substring(), or readLine()), I can access their documentation in-line with either a ctrl-space or right click in either netbeans or eclipse. 

Is there some way to do this in Xcode for Apple's Objective-C/Cocoa API? 

Thanks in advance