Yvonne,
I know it easy to be nervous when confornted with such a large amount of material to learn. The best thing to do is to break it down in small pieces/sections and make sure you understand each section before moving on to the next section. It's not important whether you read the study manual or the online course first. It is important that you use the process that works best for you.
Please let me know when you come across a topic you don't understand. Email me your questions so I can explain or clarify those areas that are unclear.
Best of luck!
Jan
The OLT online course is very very well designed. It quizzes you on each page on the content of that page. And, remember you have unlimited access and unlimited times you can take the quiz, except for the final, and you have the jump pages that can take you back and forth within the content. Like Jan said, break it down into bite size pieces, which the online course does for you.