trying my first crusade and need a little mechanical help

No it's not normal.

Crusades you just click the crusade flag on the left and once the summary comes up click lefthand side + to offer to join, pick one of the guys (I usually do the smallest one) offered and go down there.

It should quickly become obvious where you're going. If you're a 1066 start like 99% of people are the best you can probably get out of early crusades is the Crusader trait for you/heir/vassal/whoever (personally lead troops landing in The Zone) because more than likely your opponent is the Seljuk Turks and has doomstacks that would make the HRE blanch. The Crusader trait is nice though and gives a boost to relations with anyone else with it as well. Just remember to disband before it eats you so your personally-led army isn't suddenly leaderless because you died.

You might get lucky and siege a province, I tend to just take my personal levies down with me and see what I can get before they get around to sending the army after me - early Crusades are rarely a victory because the dukes and counts are all signing up like crazy but the guys with real power are busy and don't commit until too late.

tcplotts said:

And a final question: how many troops do I really need to get anything out of this or am I better off just waiting until I'm, well much bigger. Currently King of Ireland.

Click to expand...

You won't really get anything out of it unless you can provide the most contribution, through taking lands, killing (and losing) soldiers etc. And even if you do, it will be a constant headach to administer most Muslim lands from the other edge of the map like Ireland.

You could always just gather up all your vassals and your heir and land them all in the crusding target, just to get everyone a Crusader trait so that you'd be one big happy realm, though.

Going on a crusade att all gives every involved character the really nice crusader trait, which is quite useful.
Managing to siege a few baronies can usually pay for the involved troops, so it doesn't necessarily cost you anything. You don't get any land unless the crusade is a success (which the first one most likely won't be) and you're the biggest contributor (which is almost impossible as the king of Ireland).
Since you don't get any land anyway, your best bet is possibly to siege and sack province far away from the Crusade target. Those don't give you much contribution, but the Doomstacks are usually busy spilling christian blood around Jerusalem, so if all goes well, you can make quite a bit of money off of that.