I have already taken 70-236 and 70-237. I am now studying for 70-238. I am reading the Microsoft press book
http://www.amazon.com/MCITP-Self-Paced-Training-Exam-70-238/dp/B002CIE5HW/ref=sr_1_1?ie=UTF8&qid=1333987454&sr=8-1 and believe it or not it is a great read. You have to read this two or three times but the information I have learned is great.
Many of the items are questions I have always wanted to know but did not ask and the book does a fairly decent job explaining the items.
Once I am finished reading the book in which I planned to be done in 3 weeks. I will then take the test and will have my MCITP in 2007 and then on to 2010.
I recommend playing around with the small organization, large organization and complex organization if you have Virtual machines. I have learned a great deal about AD deploying exchange in those types of environments. Most folks just cater to the environment
in which they work in rather, than going outside and examing building a resource forest and getting the Global address list to sync with each other in different forests. Grab as many white papers and blogs as you can. You just do not want to be certified paper
but be able to master the subject at hand.
There is an amazing pack of free network admin tools.
click here to download it