How to add a bookmark button to your site
The simplest method would be to go to addthis.com and get the code that does this for you.
To save you some searching around the addthis.com, here's the exact code you would need.
<!-- AddThis Button BEGIN -->
<!-- AddThis Button END -->
Just add this code wherever you would like to place the bookmark/share button.
This method is doubly useful, because it also adds a lot of other sharing services to that button.
I've seen many sites take up a huge amount of space to add this button, where they could've put something more useful. Web page real estate is very limited, so use it effectively. Most users know how to bookmark a page.
With this code, all you add is a small link. When visitors hover over it with their mouse, they get a pop-up with a wide range of sharing options, in addition to the "Favorites" option.
If you create an account with addthis.com, you can also track how many people shared your pages.
Well, anywho, that's all there is to it. Any questions? Leave them in the comments below.