In Kindergarten we use the Fundations phonics program to teach the children about letters and their sounds. When all of the letters have been introduced, we learn how to put the letters together to make words.
Below is a link to a wonderful Kindergarten webpage, titled Mrs. Jones. This homepage has great activities to do at home with your child that will reinforce letters and sounds.
http://mrsjonesroom.com/letter/all.html
Below is a link for the free site Starfall. This site has many fun activities that reinforce shapes, colors, letters, sounds, nursery rhymes, numbers, reading etc. to do at home with your child.