Once you have your text selected, press Ctrl, then P. The Ctrl key is on the left-hand bottom side of your keyboard. Do NOT just hit the Print icon at the top of your browser; it will not exclude graphics (that is, unless of course you want the graphics included).
When you hit Ctrl P, you'll see a pop-up window appear that is labeled Print. You'll have the option to further individualize your printer output. In order to save a tree, always select the radio button labeled "Current Page"; this will only print the page that you have selected text from and none other. Press Ok when you're all done.