Nethack-likes have limited scrolls of identification and usually no learnable identify spell or a reliable identifying NPC.
This actually a common complaint for d1
There is no "Identify book"(exception:in Hellfire expansion Bard skill is Identify), you have to buy scrolls(100g) , or pay for id(100g). In d2 you can stack scrolls in books(also works with town portal which has a skill book only in d1/hellfire).
Identify
In Diablo and Hellfire, items can be equipped and used without being identified (magic/unique items must be identified in Diablo II before usage).
All magical and unique items found in the dungeons or given as quest rewards are unidentified, and must be identified (by this spell or by Deckard Cain) before their special properties become active.
It is not recommended to always identify items. For instance, identifying the Gotterdammerung activates the All resistance equals 0, which could make the item detrimental depending on your character and build. Note that items that have only negative modifiers would be worth less after being identified (plus you also wasted the 100 gold for the Identify scroll or Cain's service), indeed such an item is more effective when not identified. If you plan to keep the item for while, repair it first before identifying it; once an item has been identified the selling and repair costs go up considerably (assuming overall positive modifiers).
Identify is not found on spellbooks, and can only be cast from staff charges or scrolls.