The icons on Google's maps are embedded into the map images themselves. There are no separate icons for things like the little golfer dude who represents golf courses or the pine tree that represents parks.
Other icons for controls and the like can be recovered easily via Firefox. Just right-click on an area of the page off the map and select "View Page Info." At the top of the popup window, click the media tab and you'll get a list of all the images on the page, plus a preview area at the bottom. Save whichever icon files you want from there.