I am new to Cocoa development and I am trying to create UI layouts using what I consider to be the \"standard\" layout that is shared by apps like iTunes, iCal, iPhoto, Bill
The range of applications you mentioned is so wide that it is impossible to give a direct answer.
In general, the item you call a Library is usually an NSOutlineView (for hierarchies) or an NSTableView.
The main panel really depends on the actions contained within, same for the utility panel.
My suggestion is to read Apple's Human Interface Guidelines for OS X. This will give you the best overview of how to do things. Other than that, the actual implementations are too dependent on the individual program.