The read-aloud book for this time period was The Door in the Wall. It is a Newberry Medal book that I highly reccommend. It is such a great book that my children begged me to read more each day. I tried to stay with one chapter a day, but sometimes I gave in and read two.
The castle kit Make This Model Medieval Castle was included in the deluxe package for Rome to the Reformation. We just followed the instructions (I did a lot of the cutting, because it's very important to have straight lines.) :) We (9, 8, 5, and 4 year olds) all worked together to build it. It was difficult for the little ones so they mainly just helped with some of the gluing.
Here is a picture of our castle (can't figure out why it is sideways):
