lot of people are looking for STS on this site. But do you know STS just can help you 20% of your exam? If you don't believe just go ask the person who already taken the exam. the best way should be:
1. try to get at least 2 sets of real exam papers.(I agree that is not easy)
2. download some documentations(for example, "SQL reference manual" for part1; "concept" for part 2) from oracle website.
3. go through the real exam pager again and again. refer to reference manual for more understanding. two weeks can pass 1 part.
since oracle give the questions in real test are very repeatible. usually 2 sets passed exam can cover 77% of questions you will meet, which is enough to pass. 3 more sets will cover 98%. Think about how easily you can pass the exam.
if you want ask detail about exam samples, contact me to:email@example.com