Preschool can be tricky for some to figure out. Few companies provide preschool curriculums, especially those that are appropriate for very young learners.
My daughter was 2 when I started preschool with her. Many preschool activities were too advance for her physical development (i.e. dexterity). My goal for preschool was to help her develop better muscle control for writing while challenging her mentally.
What I found was the Step Ahead series by Little Golden Books. I used the 4 titles in the series that were available at my local ALCO/Duckwalls and was instantly impressed.
I'm Ready for School
This book taught such concepts as left & right, matching, colors, and drawing. The book also taught some basic reading skills by identifying pictures. Much of the book is sticker based and what wasn't, she was able to complete with a crayon.
Before I Do Math and Counting 1 to 10
These two books were great for introducing number concepts and for number identification. They are both set up in a similar presentation style as I'm Ready for School. The first title here teaches comparisons and number identification. The latter title helps with counting and number identification. I also used it to help with some basic writing skills by having her trace the numbers on the sticker pages.
Before I Write
This was probably my favorite book of the bunch! The work starts out with straight mazes about 1" wide getting narrower over the next few pages. It then adds curves and sharp turns before working to staying on a dotted line. A few letters are introduce on the last few pages written two way - maze and dotted line - with space to write on the child's own.
These are what I started my daughter using. It took us a couple of months to get through the four books before moving on to more advance books in this series and other companies' materials. This series though was my absolute favorite and one that I recommend to everyone who asks what to do with their preschoolers who are ready for school.