The key to passing this exam is to have experience in many different types of SharePoint development. Yes, it is important to know how to develop SharePoint Web parts, but much of the exam focuses on other types of development. For example, you will need to know how to customize the SharePoint ribbon and how to build SharePoint workflows. By far the most important thing that you can do to prepare for this exam (aside from gaining hands on experience with SharePoint development) is to spend plenty of time going through the exam objectives with a fine tooth comb.
Recommended Study Resources
There are a number of different study resources available for this exa,. Some of the most highly rated study guides include: