Cranial nerves

Some cranial nerves carry sensory info, some motor info and some both. A good way to remember which ones do which is:
Some Say Money Matters But My Brother Says Big Breasts Matter Most -- words that start with 'S' = sensory, 'M' = Motor, 'B' = Both

Nerves and nuclei

These nuclei are areas of grey matter, and damage to them can have a similar affect to the severing of an actual nerve. Axons to (and from) cranial nerves synapse first at the nuclei.

Arrangement of the nuclei

Close to the midline are the somatic efferent nuclei, such as the oculomotor nucleus, which control skeletal muscle. Just lateral to this are the autonomic (or visceral) efferent nuclei (for instance the Edinger-Westphal nucleus that controls tears).

There is a separation, called the sulcus limitans, and lateral to this are the sensory nuclei. Near the sulcus limitans are the visceral afferent nuclei, namely the solitary tract nucleus.

More lateral, but also less posteriorly, are the general somatic afferent nuclei. This is the trigeminal nucleus. Back at the dorsal surface of the brainstem, and more laterally are the special somatic afferents, this handles sensation such as balance.

Another area, not on the dorsum of the brainstem, is where the branchial efferent nuclei reside. These formed from the branchial arches, in the embryo. This area is a bit below the autonomic motor nuclei, and includes the nucleus ambiguus, facial nerve nucleus, as well as the motor part of the trigeminal nerve nucleus.

Cranial nerves in non-human vertebrates

Human cranial nerves are evolutionarily homologous to those found in many other vertebrates.
The first ten pairs of cranial nerves arose in the common ancestor of tetrapods (amphibians, reptiles including birds, and mammals). Cranial nerves XI and XII evolved in the common ancestor to amniotes (non-amphibian tetrapods) thus totalling twelve pairs. These characters are synapomorphies for their respective clades.