Ultima II sections on websites can be found:
Enemies from both the overworld and in dungeons are listed at at the RPG Classics Ultima 2 Shrine.
The main foe is Minax (Codex of Ultima Wisdom page).
The Ultima II Encore CD-ROM Game Manual is on the Ultima Web Archive.
Another Ultima II manual [TXT] used to be at Quill Dragon's Lair, but is now being hosted here since that site is no longer available.
The following special items appear in Ultima 2:
Items left by slain enemies are listed at the RPG Classics Ultima 2 Shrine.
Maps of Earth can be found:
Space maps can be found:
There are Ultima II maps of all the planets and times at an Internet Archive snapshot of Virtues Dragon's Codex of Ultimate Wisdom.
Find out more about the story of Ultima II:
Fallible Dragon has written a walkthrough for Ultima 2. It can be found at the Ultima Web Archive.
Clues for finishing the game by Adric can be found in: