Apple Newbie-- Fontbook problem pls help!!

[poredoor]

Hi, I am having a problem with fontbook. First time apple buyer. I accidentally deleted fontbook apps, silly me. I saw on you tube about installing new font. You just click the downloaded font and a new window pop up with "Install font" button. Since I deleted fontbook app, I tried to download app named font book V4.5 which I don't know it's the same one that came with apple. It seems different, there is no "Install" button for me to click instead there is just window with font table index show up. How can I solve this problem. I really would like to install more new fonts but no idea how to deal with it. Please help