Also get all rocks and sticks, when you get into the swamp, theres a frog face, you need to use frozen spell so you can step on the quicksand (careful, insta kill), put one rock into the frogs mouth, hit its nose and.... its worth about 100 crowns each one!!! You can also try other objects.
If you know some partner will leave you, right before it happens take all his/her stuff.
When you get poisoned, go to a calm place, rest until the character dies, then have other character use heal spell and rest again.
Last, do not buy anything in the swamp area until you own their respect (half price).
Lafazar: This game has a surprising amount of really crappy "named" weapons that sound impressive but are much weaker than what you are currently using. And even if they do have a special effect (which most don't), it rarely makes up for the loss in might. Just drop or sell anything that has less might and you'll do just fine.
Exceptions that could be useful:
-One or two weapons have a "right click on portrait" use, so always try that before selling the weapon.
-The crossbow Valkyrie is one of the best weapons in the game and always hits.
-Keep the two emerald blades.
-The Axe "Dominance" has a 5% Chance to kill any enemy , but it seemed to happen much more rarely to me
-The Great Axe "Master" increases the Rogue Level