Make a list of basic vocabulary, such as words for animals, clothing, foods and parts of the body. As your child learns, expand the vocabulary lists. Buy Spanish tapes or use online resources to learn to pronounce the words. Use an English-Spanish dictionary to look up words.
Play games, such as the matching game Memory, and name the pictures in both English and Spanish. Ask your child to repeat after you. When you finish the game, review the words by pointing to a picture and asking him to identify it in both languages.
Read lots of simple picture books. For each picture, identify the image in English, then in Spanish. Once your child is familiar with the pictures, tell her a Spanish word and have her find the correct image. Practice and repeat the words.
Teach your child phrases in Spanish the same way you teach English phrases. At snack time, use Spanish phrases for "please" and "thank you." In the morning or at night, greet your child with the appropriate Spanish greeting.
Watch Spanish cartoons, especially shows that your child is already familiar with in English. Most DVDs have an option to make the language Spanish, and by watching a favorite cartoon that he already knows the words to in a new language, your child will begin to pick up on new vocabulary and grammar rules.