Teaching Computer Lit. in Developing Countries?

Pro777 asks: "I am a US Peace Corps volunteer currently teaching 'Computer Studies' at a High School in the Republic of Samoa, in the South Pacific. Anyways, myself and other IT teachers are having a difficult time finding a good digital textbook to teach basic skills such as basic computer architecture, word processing, and using spreadsheets. Real textbooks are cost prohibitive, and a lot of what is found is too high level for our students. Any suggestions?"