More of the same.
What’s surprising to me is how much of a gap there was between the first set and this one – almost a full year! (That’s assuming the date of the first set is anywhere near correct.)
As with the first set, you can read the example encounter descriptions at Greyhawk Online. One thing of note is a monster called an Aurotyugh – basically a pile of gold that can soften armour. It seems to have the barest connection to the Otyugh that would appear later in the Monster Manual.
A date for this Set is incredibly hard to pin down. The copyright date is September 21st 1977 but that’s also the date for Set Three. And they were registered 5 years later in 1982, so I don’t think that’s very reliable. Echohawk’s list on Enworld (although it’s unclear where the information has been obtained) has a date of April, which seems much more likely.
The other major clue I could find is in White Dwarf magazine. Issue 1, June/July has an ad for Games Workshop which lists Set 2! White Dwarf #2, the August/September issue, lists Set 3. So I’m happy to go with April.
Likewise, Judges Guild Journal, issue M, June/July, states Set 3 is now available. Set 2 of course is also available and it doesn’t appear in the April/May issue.
The final clincher is the ad in the April issue of Dragon magazine.