This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
And I did not use any commercial exam simulators. there is tons of FREE stuff available on the net. I'd suggest to those planning to take certification exams to search the web for required material and "save your money".
Thanks Peter, Bryan and others ranchers who helped me with understanding required concepts.