Today we had a Lego preschool theme. All of my children love Legos so when I was asking him for ideas of themes he wanted to do this year I wasn't surprised he said this one. It is a great theme with a wide variety of learning opportunities plus it is just plain fun.Here is a template of Lego figures so your child can create their own on paper.
1+1+1=1 has a kindergarten printable Lego pack and some other ideas for using Legos for learning.
We had fun playing "Roll a Lego Minifigure".
I put sight words on Legos and let my son build sentences. If your child is still learning the alphabet you could just put a single letter on it. Check out this website for ideas along this line.
I had my son sort his Legos by color. You could also sort them by size. Then we counted how many we had of each color and figured out which we had the most of and which we had the least of.
We also enjoy The Lego Movie.