The Big Book of Monthly Ideas Looking for lots of monthly thematic ideas that are practical, fun, and easy to use? Then The Big Book of Monthly Ideas is just what you need! We've selected the very best units from America's #1 line of monthly books and combined them into one huge resource that gives you more than 500 age-appropriate, teacher-tested activities that span the whole school year. Save time and make monthly planning a cinch with terrific ideas for all curriculum areas. 240 pages. Preschool-Kindergarten.