Books
Teaching By Design, by Kim Voss, shows readers how to use the computer to design meaningful educational materials for children and adults with special needs. A synthesis of computer graphics, education, and crafting, this book represents the author’s considerable expertise in customizing educational materials for her daughter with multiple disabilities as well as teaching other parents and teachers to create them too.
Full of instructions for designing and adapting materials and strategies for using them--including a time-saving CD-rom of templates--Teaching by Design is useful to parents and teachers of students of all ages with a wide range of disabilities. Design and customize lotto boards, interactive spelling cards, game pieces, playing cards, matching games, menus, fill-in-the-blank decals, handwriting transparencies, and more, to teach visual perception, math, language, communication, reading, handwriting, and self-help skills.

Both of Patricia Cunningham's books provide a developmental approach to teaching reading. Although the activities are not designed for children with multiple disabilities, many can be modified and designed utilizing a computer.
Cunningham, Patricia M. Phonics They Use: Words for Reading and Writing, Harper Collins College Publishers, 1995. ISBN 0673990877.
Cunningham, Patricia M., Hall, Dorothy P. Making Words: Multilevel, Hands-On, Developmentally Appropriate Spelling and Phonics Activities, Parsippany, NJ: Good Apple, Inc., 1994. ISBN 0866538062.
What a wonderful resource this book is by Wilma Miller! It provides "practical strategies, materials, and activity sheets for the diagnosis and remediation of all types of reading disabilities."
Miller, Wilma H. Complete Reading Disabilities Handbook: Ready-to-Use Techniques for Teaching Reading Disabled Students, West Nyack, New York: The Center for Applied Research in Education, 1993. ISBN 0876282494
While this book was written for teaching children with Down syndrome, it is an excellent systematic approach for teaching any child to read. Patricia Oelwein suggests for some reading activities the use of the same plastic letters by Lakeshore Learning Materials which match the font in School Fonts for Beginning Writing.
Oelwein, Patricia Teaching Reading to Children with Down Syndrome: A Guide for Parents and Teachers, Bethesda, MD: Woodbine House Publishing, 1995. ISBN 0933149557.