I like presenting - with the overhead onto a white board and then use colored pens to point out items. Its like leaning over a student's shoulder and pointing something out to them - it is iterative, simple, quick, dependable. The quality of these gets better all the time. I don't show a lot of Web during class, but rather things I get from the web.
Publishers are great at supplying - material.
I am starting to find more that is suitable for food science. This is the best part. Students can go to this page to view past homework assignments, solution sets and anticipate future homework assignment dates. A white board combined with an overhead projector. I like presenting graphs, figures, pyschrometric charts, etc.