Have you searched the forums? There are loads of posts about this.

ericca wrote:

may i know from where i can change my font size, font style?
and also... the layout of skins?
and... how to create button for 'previous page' and 'next page'?

First take a look at [url=http://b2evolution.net/man/2004/06/16/evo_skins] what is evoskins [/url]. Then using the skin switcher and [url=http://skins.b2evolution.net/] skin website [/url] you'll choose what skin you want to modify. So you just have to go to its folder (/skin/your_skin_name/ ) and modify css file.

Of course modifying an evoskin means knowing Css and (x)html. ;)

Moving to client-side forum, since this is a CSS question.

Look in the skin folder (blogs/skins/skin_name/) for a file with a ".css" extension.

Open it up in a text editor. The "font-size" property is the one that you want to change. http://www.google.com/search?q=css+font-size