To see odorant molecules in the OdorDB (follow the Data link), and to see the olfactory receptors in ORDB that they experimentally shown to bind, (select O.R. by Ligand link).
Both links are present as buttons on the left panel.

To search for odorant molecules based on their attributes or identities: Molecular Formula, Chemical Abstracts Service (CAS) Number and Chemical Class: Select Search from the left panel.