If you want to share your computer screen with students and provide a narrative with it you can use a process called screencasting. You will need for this some screencasting software and a decent microphone plugged into your computer. There is a great deal of software out there but most of them are free to try but will set you back a few bucks to buy it. Most of them are not very expensive but there are a couple of completely free versions which i could recommend for you.
First is my personal favorite Jing from Tech-Smith http://www.techsmith.com/jing.html. This is a free download that allows you to screencast with sound for up to five minutes. The software comes with a small semi transparent icon which sits partially hidden at the top of your screen which can be opened at any time to begin a screencast. The screencast is stored in your account where you can get either a link to send to others or an embed code to insert the screencast in a site. Jing has very good documentation with its and good support from Tech-Smith. The only real downside to Jing is its short record time of 5 minutes. For longer recording you will need to purchase the upgrade version. If you need to record longer recordings in the free version you would need to create a series of sections or chapters to complete the project. This is not necessarily bad since breaking down longer videos into shorter segments is actually considered a good practice. Below is a Jing example from my archive: http://screencast.com/t/U3BA2Aq3A
The other I can recommend is Screenr http://www.screenr.com/. Like Jing, Screenr is limited to 5 minutes of record time unless you upgrade to the “Pro” version which has a cost associated with it. There are a couple of significant differences between Screenr and Jing. Screenr is in an online format. There is no software to download unless your Java software on your computer is outdated. If it is you will be prompted to download the Java updates which is usually not a problem. The other major difference is that the record web page for Screenr must remain open while you are doing any screencasts with it. This means that you will need to be careful manipulating web pages while working with this and take care not to shut down the Screenr record page by accident. This effectively shuts off the video recording. Screenr also provides both a link and an embed code for your video screencasts.
Both of these products will give you good quality screencasts but do not expect HD quality. Also consider that the sound quality will only be as good as your microphone. The best part is that they are free and with some planning you can create some good video segments from your computer screen.
Next week will be we be looking at digital video recording equipment from the cell phone through some higher end equipment and focusing on what would be the best choice for you if you decide you want to do some digital video recordings of lectures and demonstrations.