When working with students with moderate to intensive special needs it can sometimes be difficult to know where to begin. The following two books have been extremely helpful for me and my colleagues in helping us plan IEPS and one-on-one instruction.
Behavioral Intervention for Young Children With Autism: A Manual for Parents and Professionals by Catherine Maurice is a great resource for setting up "programs" for teaching even the most basic skills (such as sitting in a chair) to students with autism. The book contains a list of skills for various curriculum levels and then maps out how to teach each skill. It even describes what cues and prompting can be used.
Teaching Reading to Children With Down Syndrome: A Guide for Parents and Teachers by Patricia Logan Oelwein helped me completely change my approach to teaching reading to students with intensive special needs (not just down syndrome). The aspect of the book that I found most helpful was the process of teaching sight words which focuses on the most functional words for the child and uses a very repetitive, explicit method of introducing and practicing these sight words.