Install new fonts to your site using Fontburner. Its really easy to install the font. You just need to place a bit of code above the </head> tag.
The Html of your site with tags like h1,h2,h3 will be automatically changed to the Font style.
Just go to Fontburner choose your font and below it will be the code.Install it above </head> an your template and its done.
To change the text in post use Html like this
<div class="Your font name">Your text here</div>For those who want to make changes with the style of of font just edit the php script that you will get with the code of font. After editing the script upload the script to Google sites after creating a site.
Get the code for the script and replace it with the php script and the changes will be done.
If you have any doubts you can contact me through comments and I will be happy to help.