I also use Camtasia, and find it to be a very useful tool; but not for podcasting. Podcasting is a completely different animal than streaming video as you are talking about.
If you are interested in student learning and multimedia you might want to check out Myeres book, Multimedia Learning. He done extensive research on this topic and his findings are very interesting when it comes to visual and auditory learners.
If you are a mac user podcasting (with chapters) is incredibly easy to create with GarageBand, you simply put the cursor on the timeline where you want a chapter and enter the name of the chapter.
If posting PowerPoint with lecture is important you should take a look at ProfCast, it will be the best $29 you have ever spent. You simply start the app and then start lecturing, the software will sync your lecture and slides together, then save it as an MP4 file, and even posted to your host. It doesn't get any easier.
Another important distention about podcasting is the time issue. Optimally a podcast should be no more than 15 mins. You know the attention span thing.
But there's some very interesting research coming out of Georgia Tech about how a professor can record in 15 mins what takes an hour or more to get across in class.
Podcasting is catching on a major universities around the world and showing great promise. You might want to take a look at Stanford, Duke, and iTunesU to see and hear with some other people are doing.
Thanks for your interest, we're headed into a bright new phase of student learning.