all mobs follow a specific pattern when it comes to drops:
- the 4 main materials (wood, crystal, cloth and metal) change every 10 levels (1 year)
- 3 special drops which are easily identified by having the mobs name in the drop name
as long as you kill at least one mob per year you will know what the 4 main materials are, and if you are looking for specific drops you can just check the name and it will tell you. plus i think it would be more rewarding and independent of the players to go out and gather this information on their own as they play, it gives them a sense of getting better and learning stuff