There are a few things that are very important to do at home while your child is in preschool or kindergarten.
*Read to your child everynight.
Nothing will help your child to be a good reader more.  Ask questions while you are reading?
For example:
Why did the boy do this?
What do you think will happen next?
Did something like this ever happen to you?
*Talk to your child about what they did in school.  Please empty have your child empty their folder everyday and talk about the papers they have done that day.
*Give your child lots of opportunities to develop their fine motor skills.  Let them use (with supervision of course) markers, paint, scissors, glue, etc. as well as legos, stringing beads, etc.
*Count everything in your environment.  Point out numbers and letters you see.
There will be lots of time to do worksheets and daily homework.  In preschool and kindergarten this is what will help your child the most.