You add buttons to the navbar when you add pages to your web publication.
When you insert a page look for the option to add a link to the navbar. If
you did not do that then select the navbar > Format > navigation bar
properties and you can add links in that dialog.
You can insert navbars at the bottom, top or sides. Try insert > navbar and
you can use an existing navbar or create a new one.
Depending on which version of Publisher you are using, you will also
eventually need to ungroup those navbars or if you are using Pub 2007
install the Office 2007 SP2. You can read about the compatibility issue with
IE8 in other posts in this group.
It sounds like you might want to spend some time reviewing the basics of
using the program. Open Help and view the table of contents and/or perhaps
read the supporting material on the web:
http://officebeta.iponet.net/en-us/publisher/FX100649111033.aspx
Follow the links for the web building content.
DavidF