Last week I got a beta exam invite for exam “70-688 Managing and Maintaining Windows 8” (in beta it is 71-688). As with most beta exams lately, you only have max two weeks to prepare and there are no books available yet that you can use to study. Therefore I start with looking at what skills are being measured and if there are preparation guides available. From there on I start looking for relevant learning resources for each subject and adding them to the skills that are being measured for easy future reference.
I hope it is useful for you as well.