I add a layer package to may content but when I try to add it to the map the search show no result for my layer..
Presently, you can only add map services as layers to web maps. We're working on supporting layer packages and "web enabling" them so that they can be added over a web map.
Fawna - Are you having trouble clicking the Basemap button on the toolbar of the Map? Can you provide more details?
Thanks,
Mike