This attractive introductory level workbook has all the things you need most to teach Hebrew to a child 4-9 years old (that fleeting "golden age," when you should be teaching at LEAST one foreign language). One of the best things about it is that a child who can read at about kindergarten level can do the workbook with little or no help. (Tell them they can play 10 minutes of video games for every page they finish and the book will be done in no time. :-)
Also get a great book called "Reading Hebrew: A Programmed Instruction Book" (by Adler & Yudell ISBN
0874412153), which is also a superb workbook for introducing a first-time beginner to the Hebrew alphabet.