I just passed PSM I today by self study.
In addition to all resources already mentioned, I also found the following to be very very useful. http://www.pluralsight.com/training...ndamentals
The course is Scrum Fundamentals authored by David Starr.
Unfortunately Pluralsight does charge $29 a month for membership, but on the whole I've found that the quality of their library of courses to be worth the investment. The minimum commitment is just a single month.
I don't work for the company or have any other connection, I've just found it to be a great resource.
Hope that helps.