I came across this today, the center for early literacy learning and thought it might come in handy for families home during our mid-winter vacation. There are quite a few links and I only clicked on a few but it seems like a good resource. There are literacy ideas for infants, toddlers, and preschoolers (scroll down to reach the section about preschoolers). They also have some interesting videos here.
On that note, I hope you're having a fun vacation filled with lots of playing, reading, and exploring!