My wife's the producer in the family but in her absence, I can give a quick overview.
- Need a way to capture video. She uses a card that has TV video in and out - mostly for development. She could get away with just having TV In. She's also used a digital camera that can capture 10-20 seconds of MPG video.
- Software to edit video. Adobe Premiere is what many people use, but the learning curve (and price) is pretty steep. She uses something she got for around $100 which does basic scene editing, voice over/sound effect synchronization, and titles. Seems to do what she needs. When she gets home, I'll find out what package she uses but IIRC, she picked it based upon a pcmag.com review. (You might want to search there for "Create Movies")
- Delivering the video. Some formats, particularly those suitable for long videos require that you have a server capable of delivering streaming video - so it starts playing before the download is finished. Most formats can be embedded in a page as static objects, but you have to wait for the download to complete before they start playing.
You'll pay a premium for the capability to stream media. The specialized servers involved have high license fees, and bandwidth gets eaten at an incredible rate. Hosts that offer cheap streaming media packages often have overloaded servers so the stream is cheap, but slow. Googling for "streaming media" will turn up a lot of informational sites.
So, without knowing a whole lot more about it, I'd say your platform/format choices are driven by determining the quality/performance trade-off you're happy with.
Cost choices are price/performance point of a streaming host and the editing software package.
And time choices are the learning curve for the software.