I checked out this vintage Sesame Street Home Video title from my local library years ago looking for something on teaching young generations about the fun of reading. This video fits the bill.
Big Bird, who runs his Reading Hotline, as well as some of the other characters show kids how reading and rhyming go well together. The concept of replacing the first letter of a word is a terrific way to teach kids about reading and rhyming as well as sounding out the parts of words. Some classic segments seen on the video include Ernie and Bert's rhyming game and the song, "Fat Cat."
Try looking for this vintage Sesame Street title on YouTube, or try looking for a video copy on eBay.