Hello,
Are there any programs of there that will allow me to take screenshots or video demontrations? Thanks

the only way to do that is with XDK...and its a pain in the ass to find tools for it.

the other way is with EvoX dashboard. push the blackbutton anytime when u are using EvoX, then FTP to the E drive and put the screendump.bmp on ur computer, and theres a crystal clear image of ur dashboard

there are 2 ways to take screenshots in games.
1) buy a TV capture card for your PC.
2) use the XDK with a debug bios. (quality is better with this method)
it's not that hard to use once it's installed but you just have to be careful when installing the xbox files. (my installer does this automatically).
you can also check this guide.

Do you know of any places where I can see video demontration of programs such as xbmc?

video demonstation of XBMC? i'm not quite sure what you mean but if you want to see how it works, why not just install it on your XB?