FREE dinosaur doubles printable for Kindergarten: numbers within 20. Solve, cut and paste.
5.5.5 Finger Patterns: Once double facts are embedded (and children can count 2 collections, in case they need to do that to help) they could play this game.
Here's a set of Numicon resources on finding doubles.
Flying into First Grade: More FREEBIES!!! Doubles and Weather!!!
Doubles Facts Freebie
Finally in First: Double Trouble and a freebie
Math Doubles Song--have the kids come up with little rhymes for the larger numbers
Number - find the missing numbers.
How To Integrate Nursery Rhymes Into Your Classroom Lessons - Whos Who and Whos New