With regard to the old-school “hack-and-slash” dungeon I mentioned upthread, you may well find that there's precious few about for “novice” players with 1st-level PCs and DMs trying to get a grip on the game – at least as far as any “official” contemporary publications are concerned. Indeed, I can’t really think of any off the top of my head but I’m sure others can provide them.
A solution for this phenomenon can be using the map for the example dungeon on page 95 in the DMG. Then, after the players have created their PCs, you just inform them that they find themselves on some stairs leading down and that a room seems to be at the end of it (room 1A on that map).
When the party get to the room, you tell them its dimensions and where the exits are, and then roll dice on “Table V. F: Chamber or Room Contents” on page 171 in the DMG to determine what’s in it. If the result is 1-12 or 18, you just tell them that there's nothing in the room and it’s on the to next. The table is pretty self-explanatory, so, if monsters and/or treasure, tricks/traps, or simply treasure are indicated, just refer to the relevant tables on the pages that follow and then to the MM as applicable.
A couple of notes.
1) A result of 13-17 leads you to the “Dungeon Random Level Determination Matrix (d20)” on page 174 in the DMG, where you have to roll dice to determine the “level” of the monsters encountered and then stat them out using the info in the MM.
You'll see that this allows for the party to run into “third-level monsters” on their very first outing. Although the notes under “Monsters Encountered Adjustment for Relative Dungeon Level” on page 174 (ah, yes, by the way, welcome to High Gygaxian) do mean that the maximum number of ghouls and giant lizards in this case will be two and one, respectively, neither isn’t very likely to end well.
There's a couple of things you can do to deal with this “problem”.
First, you can just let things happen and see where it gets you, accepting that PCs dying
en masse is just part of the game. Of course, this will at least in some part depend on whether your players are willing to accept that their PCs are dying all the time. However, without going into this phenomenon too deep, there
is a certain “method to this madness”. First, it’ll force players to think differently of their PCs than they may have until now, which will rather be to their advantage for what lies ahead in their 1E career. Second, in my experience, many players will find that the ever-present risk of dying adds to their excitement and, if you’ll forgive me, an “unforgettable game experience”. Third, also IME, many players will find that they will develop a strong bond with those of their PCs that
do survive to get to the higher levels, which leads to all manner of interesting dynamics.
In this light, it wasn't at all unusual for players to run multiple PCs simultaneously to increase their chances of survival.
Second, since you’re all only trying to get acquainted with the mechanics of the game, you can just decide to roll again using only the “1st-level” monsters table – or use only this table to begin with.
Third and perhaps obviously, you can simply ignore encounters you think will lead to too many dead PCs - just another empty room. This is also true, for example, for encounters you think may be too complicated to stat up in a jiffy, such as
NPC character parties and, say,
49 berserkers.
2) Doing things this way will lead to sessions some of you may not recognize as D&D sessions. There’s gonna be lots of rolling dice, paging through books, trying to figure out and implement rules, and more rolling of dice on your part. However, you may consider including the players in this process. Let them roll the dice, let them consult the DMG – perhaps even the MM. This way, all of you can get to grips with how the game works at the same time, and it might even lead to new DMs being born. I suppose you could see these sessions as multiple “sessions zero”.
Similarly, since the encounters are gonna be as big a surprise to you as they will be to the players, you can roll up your own PCs and have them be part of the party on their first descent into the…, um…, upper depths of the earth.
3) Although you should peruse the rules for awarding XP under “Adjustment and Division of Experience Points” on page 84-86 in the DMG to learn that XP is not only awarded for defeating monsters but also for treasure gained (and, of course, just to read some more High Gygaxian), it’s probably best to ignore most of what is written there, if only during your sessions zero. The tables starting on page 196 in the DMG give experience values for monsters in the MM and you’re probably best served to just hand out the XP mentioned there.
Finally, although I am not at all familiar with the OSRIC rules many folks mention above, I understand that all these rules do is present the 1E rules in a manner that is much easier to work with, which may well be good thing. However, if you haven’t already done so, you may well want to consider the magic of immersing yourself in High Gygaxian and the rewards it can bring. In the words of a wise and above all notorious liquefactionist:
Finally, while I will continue to joke about High Gygaxian, 1e had the perfect marriage of of form to function; the act of reading and understanding the game introduced you to the idea of something new and mysterious. It was impossible to delve into the baroque and contradictory language of Gygax without starting to feel the stirrings of something greater just waiting for you. The language invited you not just to play, but also to create.
And rewards there will be.
EDIT: + "a"