Poisons deals with your ability to spot and use the various natural poisons which grow all over the Avalonian mainland. Poisons can be discovered in a location by typing POISONS where you will be informed of any poisons you can spot. You ought to try and ANALYSE all these to gain some idea of their habitat and worth. As you gain competence in Poisons you will find the number of poisons that you can use increasing. When a poison is found you must PICK it. Once picked you must PREPARE it, and when prepared it will 'keep' for much longer - generally to be placed in a herb pouch, shop or used according to one's skill.
Bringing about a poison's effects is done via various commands, depending on the specific poison. You may be able to APPLY it to yourself or someone in your location if it is a paste; SMOKE it, if it is to be smoked, using a pipe; EAT it, if it is to be ingested; or PUT it in a drink or item of food if it is to be drunk/ingested. See HELP BREWING for info (if you have the skill) on creating poison solutions. Concealing poisons in drinks is a very sneaky way of administering the effects to somebody unknown to them. You can RUB poisons on weapons or arrows so that when you use the weapon or fire an arrow, the poison is applied to the person you strike. See HELP GARDENING for help on planting and dealing with herbs.
NOTE: While the Poisons skill is traditionally the domain of the Thief and Ranger, it is possible for the everyman to become familiar with its use and even develop the skill to a similarly high point as the original professionals - details on this can be found in HELP HERBALISM or by seeking a member of the Thief or Ranger profession directly.