I presume you have been through the Java tutorial about layout managers? In fact anybody ought to try the Java tutorial first for most questions.
Cay Horstmann (cf Horstmann C, Cornell G, Core Java 2, vol I-Fundamentals, Santa Clara: Sun Microsystems Press, 2004, pages 430-440) and this website) has his own ideas about GridBagLayout, and has a "helper" class which you can download from the website cited. I agree with him that it makes GridBagLayout much much easier to use.
BTW: If you really are a "greenhorn," borrow the book from the library rather than buying it. It is not suitable for beginners.