I'm guessing that CanoScan Toolbox doesn't know which applications to use for each of the functions.
When you select the email function, for example, it needs to know which email client (such as Outlook Express, Thunderbird or Windows Live Mail) you want to use in order to send the mail. (Note that you can't launch a web-based email system directly from the scanner).
Similarly, CanoScan Toolbox will need to know which printer to use for photocopying and which image editing program you want to scan an image to.
Try opening CanoScan Toolbox (from Start > Programs > Canon > CanoScan Toolbox 7.0) to see if you can get anything to work from there. (I never use the buttons on the front of my Canon scanner).
For example, try clicking the 'Mail' button. You'll see a box labelled 'Link scanned images to'. That shows which email program should be opened. If it's blank you need to click on 'Set' and then on your chosen email program (e.g. Outlook Express).
Repeat with the other buttons.
If you've not got an image editing program which can accept scans from a TWAIN device (such as your scanner), install Irfanview:
http://www.irfanview.com/
(or your own choice of program, such as GIMP or another alternative)
Chris