Do you mean to add it to your favourites so you can find it quickly?
If yes, then.. in the menu bar at the top of your browser, there should either 'Bookmarks' or 'Favourties' depending on the browser your using. (if it's Internet Explorer it will be 'Favourites')
First...Go to the home/front page of gnutellaforums, then click 'bookmarks' or 'favourties' then a menu will drop down giving you the option to 'Add to Favourties', click that. Now the home page will be in the list of your favourite sites that you can find quickly.
You can add any site to your list by doing that. It might be advisible to make some category sub-folders, as the list can get very long if you don't