This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I would suggest playing with the layout managers. Put various components on them and see how they react. You need a strong understanding of how each of the managers work. Otherwise, you will be using the null layout because ... Fill in the blank with an excuse why the layout managers won't work.