How to use video effectively?

There's any number of ways to create videos and a wide variety of different types make up the most popular on Youtube. What matters the most is the content of the video.

IMO, the "best" way to make money on Youtube is to pick up a digital video camera and show people how to do something they want to learn how to do.

The "easiest" way to have professional looking videos is probably to use something like Powerpoint then buy good looking templates and media to use in the PP videos, along with interesting, entertaining or informative content.

Another consideration for slide show style videos is ProShow (gold or producer). But again, you need to input quality to get quality out.

Powtoons is great for learning how to do simple animations, but IMO Video Scribe is the better long-term choice for that type of animation and has better licensing TOS. For more powerful animation software, I like CrazyTalk Animator Pro to make cartoon videos, but it has a big learning curve.

Then you have screen capture programs, like Camtasia, to use to teach people how to do things on their computer.

For special effects you'll want programs like Adobe After Effects or even Flash.

You should also have a good, basic editor. Camtasia has easy to use editing features. Something like Sony Vegas will give you more power and options at a good price, but a higher learning curve.

In reality, no one video application does it all and I'll often find myself using multiple programs to create a video.