Do you recommend using ImageReady to create web pages?

I only use ImageReady to slice images. That was what it was designed for originally, to make Images Ready for the web, and that is still what it is best used for. Everything else I do in Dreamweaver. This is partly a personal preference and you can do quite a bit with ImageReady, but even Adobe has a different product for creating web pages in GoLive.

My personal preference is to use the best product or tool for the job.

My personal favorites are:

Photoshop for image creation

ImageReady, used with the Photoshop images if needed.

Dreamweaver for web development work

Flash for animations

Freehand for vector images (I like Freehand a lot better than Illustrator)

I have found that Dreamweaver has some problems with ftp access to some servers, so for those problem servers I use WS-FTP.

I also don't use any templates, I always create web pages either from scratch, or based on an existing web page that I built from scratch. I just prefer the greater level of control doing it myself.

How do I capture video from my computer screen?

I use a high-end professional screen capture and editing program, so that will not fit your needs. But there is a good, relatively low cost, product on the market that does a good job of capturing screen video. It is called Camtasia from Tech Smith. Here is their web site: http://www.techsmith.com/

Their Camtasia Studio costs about $300 but it is the best low cost solution that I am familiar with. There are probably others out there and a lot of times you will find software like this bundled with computer video cards.

As far as video format, I would recommend recording your videos as .avi files. This is an old standard and most video players can play this type of movie. I use avi myself because you can easily record larger videos, where some of the more modern video formats limit you to a specific screen size or resolution.
Also, to learn all there is to learn, just go to Google and do some searches. Try "video capture" "screen capture" "avi", I know you will think of some more.