This is a list of things discussed or identified as useful in the chat on homeschooling multiple ages.
State Standards — used for assessing progress of students
Homeschool Share — a source for unit studies, some secular, some not.
Homeschool Creations Homeschool Planner — an editable planner for those of us who are scheduling challenged.
EasyFunSchool — resource for free lessons in several subject areas (art, science, language arts, history, nature studies).
Good Night Moon Tot Trays and Sensory Bins — examples for tot school type activities for the younger children in a multiage family.