To clear the exam i will STRONGLY recommend all of you to follow K&B book.Read the book well.Try to understand the topics.Do the self tests properly , which will surely help you since it will clear your concepts.
Most important is that you revise topics which are quite tough , probably i felt Generics,Collections and threads as the toughest topics.So i revised these chapters atleast 5-6 times until i was very clear. I will also recommend to write some programs specially for Collections(Hashmap, hashset),Thread etc For example i was confused about how hashCode() and equals() work.What i did was i wrote few codes related to them and then tried to understand the flow.It really helped. Other chapters i revised 2- 3 times.But anywhere you are stuck, just try to write code related to it. As far as mock tests are concerned, i feel any mock test is fine.