Printing web pages has always been easy, but the result is never consistant and neither is the method. Some web sites will have you download a PDF or Word version of a web page so you can print from an external program. Others might have a link to a separate, but printable version of the page. At the worst, a website will have no other way print a page without the unneeded content and formatting. The answer is to use a separate stylesheet for printing.
Look at this sample XHTML head section:
In the sample, there are two stylesheets linked to the page. By giving the first one the media type of screen, you limit it's styles to devices like computers and smart phones that have bigger higher resolution screens. The second stylesheet is set to the media type of print. These styles will only be seen when you print or print preview a web page from your browser.
Print stylesheets are best used for hiding certain objects in a page and changing the formatting to be more readable and appropriate for print.
Setting objects to a display value of none, will remove them from the page layout completely.