H.K.
There are outdoor swim Lesson through the YMCA all summer - they have mommy/daddy and me where you can get in with the child until he can swim a bit on his own then he goes to the next level and swims with the instructor(s).
They also have these type of classes indoors at the Cerritos Olympic Swim Center (in Cerritos, CA) year around (they offer private, semi-private, and group classes) - check the city of cerritos website.