AWS sells an API study guide/workbook called the API 1104 Code Clinic Reference Manual for $51.00 (member price). It has 10 self test and is the same material they teach in their workshops. The important thing about the open book code test is that you know how to find the answers to the questions in the book. The test is designed to see if you know how to use a code book and not how well you can memorize each section. If you are more familiar with D1.1 then that would be your best bet. If you are not familiar with any of them then 1104 has less info than D1.1 so most people prefer to test with it. One of the key things about API 1104 is that the index in front of the book will be a tremendous help to locate what you are looking for. Another thing is to determine what the key word or frase that the question is looking for is. You should order the reference material and take your time going through it (it will help you find learn how th ecode is layed out). By the 5th test in the lesson you will begin to pick up speed finding the answers. You could then begin to time yourself since most of the test supplied with the material have 40 to 45 questions. Hope this helps and good luke.
RB