One of the greatest things about CSS is that you can define style sheets for different types of media.  It seems like only the large corporate websites provide printer friendly stylesheets, but it should be that way.

You can easily create a printer friendly style sheet for your site.  Just create a copy of your current style sheet and call it print.css

Open up print.css and located all the elements that you don't wish to be printed and set their display property to none..  Usually this includes all navigation, most images, and any other undesireable.  Your printable page should only include the content, as that is what people will want when they print your site.

Finally, add the style sheet to your page.

<link src="print.css" type="text/css" media="print" />

Now when people print your site, they will get a printer friendly page.  You can test your settings by clicking print preview from your web browser.

Please note that this may take a little bit of tweeking.  When creating style sheets for printing, you should use points (pt) instead of pixels (px) for your font size.  You can set your page size in inches (in) and there are several other practices that are avaliable for printer friendly pages.