Amazon is advertising a certification kit for this exam:
http://www.amazon.com/SharePoint-2010-Developers-Certification-Toolkit/dp/0470912340
Unfortunately, the expected release date is September 2011, and this may be too late for you. You could try studying some "generic" book about Sharepoint 2010 such as (for instance) one of these:
http://www.amazon.com/SharePoint-2010-Developers-Certification-Toolkit/dp/0470912340
http://www.amazon.com/SharePoint-Development-Visual-Studio-Microsoft/dp/0321718313/ref=sr_1_7?s=books&ie=UTF8&qid=1300045773&sr=1-7
After you have studied the books and done some practice, you can go over the list of "Skills Measured" in the exam description page:
http://www.microsoft.com/learning/en/us/exam.aspx?id=70-573#tab2
Check out each of the entries in this list, making sure that you know them all. If there is something that wasn't covered in your book, search it on MSDN or Technet, and study the available documentation. After you have gone through the complete list of
Skills Measured in this way, you are ready to take the exam. This is not as easy or as convenient as following a training kit, but since the kit is not yet available, you may need to go this way.
