Creating/ Designing/ Working out with a Video
Windows movie maker itself is sufficient to create videos of your choice. It is easy to use and offers option to upload it directly into your Youtube account. Since you asked an alternative, I would like to suggest you Corel Video Studio. I used it personally and it has a lot of inbuilt templates, which helps us to create our video in minutes, particularly when we are working out with videos by assembling photos or presentations. This software itself as all the features for editing the video and refining it for perfect view in Youtube.
Reducing Size of the video
Once you create a video with Windows movie maker or Corel Video studio, the output video obtained will be of huge size and it usually takes more time to upload in Youtube. If you are uploading as it is, then keep in mind you are wasting your precious time and data usage (even though it is free). For reducing the size, use iSoft Video Converter (I am using it still now), the simple thing you need to do is to change the format to flv without changing any of the aspect ratios. After converting, the size of the file will be reduced remarkably and it creates a convenient room for uploading in no time.
Try Screen Capturing software's
If you like to create a video about how to use a software or how to use a website, instead of catching the video with camera, use a screen capturing software to record all your activities in the screen, after capturing convert as said above and upload as usual. Remember you need to have your microphone for recording your voice and correlate with the video.