CEWP = Content Editor Web Part (sorry the title only allows a certain amount of characters).
To add anything extra to your pages without the use of SharePoint Designer, you'll want to use the handy dandy CEWP. Using this technique, you can add JavaScript/jQuery, HTML, CSS, and various other scripting languages to your pages.
Here's how to add script to your pages in 2010:
http://sympmarc.com/2011/03/29/adding-s ... oint-2010/Another great post from Marc describes how to accomplish this in 2007:
http://sympmarc.com/2011/03/26/adding-s ... oint-2007/Feel free to start a
new thread to discuss any bumps in the road you may encounter.