A great way to gather resources for kids who have a developmental delay is to look at options for younger kids. And the PreKinders site has a ton of those options! PreKinders is a site for Pre-K teachers put together by Karen, a teacher in a Pre-K classroom. This site has resources broken down into easily searchable categories such as Art, Fine Motor, Literacy, Math, Printables, Themes, etc.
Karen also has a blog where she continually posts great ideas and lesson plans.
If you work with kids functioning in the Pre-K range, this site is a must!