I've found a lovely site for Children's handbell music which is all free and seems to be exactly what you are looking for http://www.theinspiredinstructor.com/music/traditionalsongs.html
It has a rhythm chart, black and white sheet music, colour sheet music, screen music and you can also listen to how it is supposed to sound (which is very helpful in my opinion)
The tunes are songs that children will know like 'Old MacDonald Had a Farm' and 'Mary Had a Little Lamb'. It's a great starting point for young children, and they will get such a sense of achievement when they can play the bells.
You may already have bells but in case you need some, there is a set for a primary school class here http://www.music123.com/classroom-kids/kids-play-20-note-handbell-set
Or if you would prefer a smaller set this one from Amazon might suit you better.
Interestingly, in the UK, there are two distinct types of handbell - "English" and "American". English are the ones with leather handles and clappers, and American handbells are made from plastic and/or rubber, which produces a similar sound. In America, all handbells are known as English handbells.