How do link to multiple blogs and have older blogs appear below? Categories?

I am new to blogging, but I have a site with three separate blogs on it (www.synapticsuccess.com). I want to have a static navigation button to link to each blog and I want each blog to have at least several prior entries listed after it.

How do I set up each blog so that I can link to it with an unchanging navigation button, and how do I get previous blogs to appear below the current one? Is this what Categories is for?

Thanks!