Hi,
The idea behind MU is that you can run multiple sites and blogs. It that what you are planning to do?
I think it would make sense if you wanted to have many people or many blogs running off of your mamaista.com site.
Imagine all your friends have a blog on your site:
http://www.mamaista.com/FredsBlog
http://www.mamaista.com/JillsBlog
http://www.mamaista.com/Helen
http://www.mamaista.com/Peter
...
Or you could use subdomains for each of the blogs.
Helen.mamaista.com
Peter.mamaista.com
photos.mamaista.com
tambourines.mamaista.com
All of the blogs could look different. All of the blogs could have different authors. The only thing that needs to tie them together is your base domain: mamaista.com
But if you just want to have one site, with a single blog then you don't need MU. If you are thinking you want to use Wordpress' CMS capabilities to administer your site, then just use regular Wordpress ( http://wordpress.org/ ) not MU.
Then you can have all your pages running on http://www.mamaista.com, controlled by Wordpress' CMS. One of those pages could list all your blog posts: http://www.mamaista.com/blog.
Unless you have a reason, you don't need Wordpress MU.