PC

As I mentioned, I do use my PC on occasion, but typically create my modules on a Mac computer.

That said, sometimes the PC is the best tool for the job. I have specialty software that only runs on a windows platform. For example, my DNA annotation and exploration tools run better on the PC. I also have created tutorials to help students with graphing their results. It is so much easier to see how it is done rather than just read about it. YouTube does post a lot of videos for this, but I put my own spin on these tutorials to make them more friendly to science student reports.

Screen Capture

CamStudio

This is a free software package that works very well.  You can download it from http://camstudio.org (they request a donation only - a very good deal).

I find it does a great job with sound recording and screen capture. It is a little bit clumsy to use, but just to get the main ideas onto the screen is pretty simple.  Essentially, I just record what I want to do on the computer and talk as I do it.  I take the finished file, and put it into YouTube. You can also create a shockwave (Flash) version, but these do not play on iOS devices (iPhone/iPad).

Captivate

This software is amazingly easy to use and creates very professional looking final products.  It is quite expensive, and the output is rendered into shockwave (Flash) output. I believe you can also make movies and load them into YouTube. The advantage of using Flash output is that you can create interactivity very easily. You can create drag-and-drop exercises, multiple-choice questions, live links, and a host of other exercises.  It is available from Adobe Corporation.

PointOFix

I love this for making quick screen grabs that I can mark up!  It's free but is written by a German group.  You have to load in an English translator, but it's simple to use, creates custom-sized swatches you can save or copy/paste.  If you get an error, the dialogue box may be in German, which is kind of fun.  It's available from http://www.pointofix.de/download.php.