He will discover that these books contain a significant amount of information about identifying types of demons, as well as methods of protection or control specific to types of less powerful demons and methods of summoning/containment/control specific to more powerful demons.

Many of the rituals are described in detail, although it appears that the vice-principal had been focused on protection rather than summoning and control, as there are no bookmarks or notes near any of the summoning rituals. Many of the protection rituals are annotated with scrawls on the bookmarks placed there; some say things like "next full moon" or "helpful?" whereas others say (for example) "useless!" or "wrong materials."

The "useless" spells and rituals appear to significantly outnumber the "helpful?" spells. Should Shun want to attempt performing any of the rituals in the books, he'd have the information he would need in order to try it, although there are abbreviations and shorthand notations that would likely need at least several weeks in the library, or the assistance of someone with demon-related or ritual magic knowledge, to correctly interpret.

(Let us know if he does want to give any of these rituals a shot!)