How long would you say it takes a newbie to finish this game?

If you choose short and easy game, which you should on your first playthrough, I would say it's about 15 or 20 hours.

I'd say, first time it only takes about 5-10 hours to irreversably ruin your tribe and get it disbanded.

i can confirm 5 hours to ruin my tribe ;)

Uh... okay. Thanks.

Don't be discouraged, though. This is one of those "losing can be fun!" -games.

And darn, it sometimes is. Damned ducks...

Except of course, that there are winning conditions.
Most of the games played don't end up anywhere near those thoug, but it's all in good fun.

You seem to be veterans at this game. Any pointers for a newbie?

Heroquests are damn difficult, but essential. You pretty much need all the details of a story (through trade or sacrifice), a good candidate, magic allocated to quests and loads of luck (bit of save/rewind might be in order). It's a multiple choice thing where you need to give the right answer every time, but the right answer doesn't guarantee success.

Elsewere in the game though, there are no patently right answers. Someone warns of broo infestation? That might be a false alarm and some other time it's the real maccoy.

The important bit is playing true to your clan heritage. If your ancestors fought elves, you'd better too. Even if it means going against your better judgement. And sometimes it's smart to do stupid things if it pleases someone who needs to be pleased.

On the original question, in total, god knows how many hours you could put into the game and still feel like there's more to see. At least hundreds. It's one of those games. You'd have to be pretty knowledgeable to race through the game in a short period of time even on short. On long games run for many dozens of hours if they even get completed.

I honestly recommend playing the long version of the game even as a newbie. The short games give you a kind of abbreviated form of KoDP where you may even learn bad habits which doesn't help later. And since you will almost certainly fail quite hard (but enjoy doing it!) it doesn't really matter if you go long. Play the game a lot! Fail, and learn from your mistakes!

One of those games where you can think you know a lot but actually it comes down to common sense in particular situations.

Small but interesting pointer I discovered at least in the early to boost your cattle (wealth)...I try to stay out of large fights (raids) if possible, especially during Planting (Sea) season and Harvesting (Earth season), it can really shortchange your food production, which leads to all kinds of problems. I have found that it's great to do small cattle raids on your neighbors once or twice a year with a *small* raiding party...I usually use just a couple weaponthanes, and perhaps 5 foot soldiers. If you listen to your ring advisors and pick the tribe they state is the weakest, more often than not, you succeed without ever being detected, and no casualties! My usual take is 25 to 32 cows or so...a nice little supplement. It's also fine to cattle raid your allies, especially if your never detected, as from what I gather from the clan history and lore, small raids are considered a type of "right of passage" activity, and a chance for young warriors to prove thier prowess.

This isn't true. There is a win condition. Look up the manual. On first playthrough it took me less than one hour, playing on average setting. This game definitely reminded me of "losing is fun" from the Dwarf Fortress documentation. King of Dragon Pass always has lots of fun.
This too.

This game is more like Civilization and the ilk. IF you like it you will play and re-play for a very long time. OTOH if you hate you'll probably play once and only for a few hours...

It's just that kind of game...

That's just not true. In the short version, you just have to start a tribe, and rule for 10 years, and you've won.

In the long version you have to become a king of all of Dragon pass, or something alone those lines.

You can definitely win, it's just very difficult. Even on easy, if you don't know what you're doing, everyone will die.