Olfactory receptor cells send dendrites up to the mucus layer. Cilia extend into the mucus, where odorants can bind to the surface and activate the olfactory receptor cells. Olfactory receptor cells send unmyelinated axons via the first cranial nerve into the olfactory bulb. The molecules bind to cilia and activate olfactory receptor cells. Olfactory receptor nerve cells connect with nerves in the olfactory bulb.
More nerves connect the olfactory tract to the thalamus.
Thalamic pathways then extend to the frontal lobe of the cerebral cortex. Direct connections are also made between the olfactory bulb and the olfactory cortex. Called 'The Molecular Logic of smell', its suitable only for people who really want to study smell in great detail as it is written at least to undergraduate physiology level.