Love the Firebug
If you design websites, I highly recommend a utility called Firebug.
It's a free Firefox add-on which allows you to inspect the elements of a web page, including CSS, HTML etc. So you simply right click on the part of a page you want info on (a button for example) then click on Inspect Element.
But even more useful is the ability to change the elements and see an immediate change to the web page. It doesn't actually change the element permanently but shows you a preview of what your change will do to the page.
This saves so much time when developing CMS websites. You can change lots of different elements until you're happy with the page then copy what you've changed to the actual website.
You can get Firebug from here http://getfirebug.com
