What does your config.xml look like. Here is a portion of mine - note the button id showing up in the toolbar too.
<Commands>
<Button caption="PaulButton" category="PaulAddinPython" class="PaulButtonClass" id="PaulPythonButtonToolFile.button" image="Images\1.PNG" message="Hello Dude" tip="Writes Hi"><Help heading="Hep Heading Stuff">The contents of help</Help></Button>
</Commands>
<Extensions>
</Extensions>
<Toolbars>
<Toolbar caption="PaulToolbar" category="PaulAddinPython" id="PythonAddIns_addin.PaulPythonToolbar" showInitially="true"><Items><Button refID="PaulPythonButtonToolFile.button" /></Items></Toolbar>
</Toolbars>
<Menus>
</Menus>
</ArcMap></AddIn></ESRI.Configuration>
my button, zooms to a selected layer
But does your config have a toolbar that points to the button by id? if not, then the button will not show up on the toolbar.
You need to check your config and see if you have a button and toolbar and that the two are connected.
and where I can see this in the wizard?
Wherever you put the source files.