i don't have much experience with teaching reading to children in general so this website really seems like a gem. the see and learning webpage is associated to the down syndrome education organization (downsed). this nonprofit does amazing research to improve education for children with down syndrome.
from what i have learned, children with down syndrome (and many typical kids like myself) learn better through visual activities. the See and Learn Language and Reading website gives a step by step guide on how to play and teach using flash cards.
they even provide the flash cards free. you can download the entire document and print it up yourself at home or you can purchase the kit at their online store. i like the idea of making my own flash cards eventually but this seems like a good foundation to start with. i can't wait to get started!