there is a little button on blog compose it looks like this
what you do is highlight the text you want to be a link , click that button and place your link in the box that comes up then press [enter]
You will then have a linked text
You can click the "view html" box and copy that code for posting in guestbooks etc.
Works in any comment like
this link is a link to your pagethis is the code for that link
<a href="http://rosellealteria.multiply.com/"> this link is a link to your page</a>