Online you will find many programs that help you create flowcharts and diagrams. But most of them come with a hefty price tag and are not suitable for people who want to make only basic diagrams. For those simple diagrams, give Simple Diagrams a try. Since it is based on Adobe Air, it is cross platform and can be used on any OS that can run Adobe Air.
DawsonITE is a blog devoted to Educational Technology. It's compiled by Rafael Scapin, Coordinator of Educational Technology at Dawson College in Montreal (Canada).