Love, reading and attention. If you enjoy your children, they know it, they thrive and want to learn. Make the things you do with them fun, all the while teaching them. Read books to them, share TV shows with them that are bright and fun with music and lots of learning.
Nothing is better for a child then the attention of a parent. They are like sponges soaking up everything you want to teach them.
As a parent, you are the best tool for them.