Free Screen Capture Software
You may like to purchase a commercial package to create fluent sceencasts, but if your budget is limited or if you just like to explore the field, you may like to have a look at one of the available free (most ly open source) packages.
Probably the most serious competitor to commercial packages, especially for small tasks that do not require expensive extras, is CamStudio. This is an open source and free screen capture software package that provides all basic and some extended features you will need to create a simple but still
professional screencast. How to create a simple screencast with CamStudio is the discussed elsewhere on this site, and there I will explain in more details what to do in CamStudio's neat interface in order to create a simple screen movie.
Another free screencast tool that needs mentioning is Wink. Honestly, it is hardly the best screen capture software because the current version does not support audio, which is really a serious disadvantage, but the promise is that audio support will be added in the next version. Compared to the commercial monsters, Wink is primitive but has a low learning curve and it can produce incredibly small files (SWF and EXE only) with decent quality, which is enough when you need a movie to send to a developer to report a bug.
Another free screen capture software package is Windows Media Encoder. Maybe you have already guessed that it does not support many formats besides the proprietary ones for Windows. But if you skip the formats issue, Windows Media Encoder offers really a lot - not only in regard to capturing images but also in regard to editing and fine-tuning them.