Oh dam! goodness knows what happened there, I did write out quite a long post but I don't know what happened to it.
Either way i'll try and do it again.
Duel wield is a passive skill that lets you attack twice. usually if you have one weapon in either hand, the game will choose one or the other to attack with. The more points in your duel wield skill, the more likely you are to get two swings of your weapon in for each attack, with the skill maxed you'll always get two hits in.
Combo is rather similar, accept that firstly combo only works unarmed, and secondly can let you attack four times.
If you raise combo and iron skin, you end up with some strong attacks, especially if you add assassin into the mix and give the monk critical hits too. Break limb also has it's uses, though I like the monk as a pure attack monster.
The main thing to remember with monk is not to forget to raise iron skin, since otherwise fighting unarmed you just don't have a hard enough hit to get through your enemies, especially deep in the dungeon.
Fighter assassin I'd personally recommend going for critical hits, duel wield, a weapon skill (probably short swords since there are lots of swords around the dungeon and you can always guarantee to get a good one).
Sneak attack is good as it provides both offense and defense.
Assassinate is good if you have anyone in your party who can wrender a target helpless, eg, a bard who can put people to sleep or a brawler who can grapple them.
If you really! want the easiest class combo, I'd recommend necromancer healer, or necromancer druid, preferable with elf or halfelf to get maximum int bonuses.
Iceblast to the head can be a one shot killer (hold 8 when letting it go), and summon bones gives you a constant free ally.
Also, since the main problem with the druid's lightning spell is the risk of creating zombies, necromancer's are great at dealing with those, indeed you can end up with zombie minians, oh and of course a druid's summon animal also gets you another rfree ally.
Healers on the other hand can heal, which is a major! help in some battles, especially if a fighter or other companion is losing a hand.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)