do you mean something like this?: http://www.openstreetmap.org/?mlat=46.9301&mlon=7.0838&zoom=13&layers=M
all right:

  1. zoom to your building and click on Permalink… on my example, you get the url http://www.openstreetmap.org/?lat=46.9301&lon=7.0838&zoom=13&layers=M
  2. make the letter “m” in front of lat=… and lon=… so you get a marker on the osm-site on your building and you can put this link on a website.

yes and no… OLM is a part from openstreetmap.de. But if you edit something in openstreetmap.org, you will see it automaticly also in OLM… OLM is just a layer, which will display some additional infos, that you can’t see on the official osm-website (there are a lot of other layers… p.e. opengastromap, Maxspeed,…