A 'Landed' Baron or Baroness is the ceremonial head of a Barony. They are called Baron (or Baroness) of name-of-Barony. They receive this title from the hands of the Crown. There is no specific length of term in office, this is determined by each specific Barony. A landed Baron and/or Baroness is required to swear fealty to the Crown for the lands held by them (at least this is the case in the West Kingdom).
A light fighter is someone who does not use "heavy" weapons (sword and shield, etc.), but instead uses missile style weapons, which can range from bows and arrows to javelins. Light fighters don't usually get to "play" except in war-time scenarios. Light fighters need to be authorized, and wear armor, but the restrictions are different from "heavy" fighters.
The list field, or tournament field. This is where the official martial competitions at SCA events takes place. The list field is usually in the center of the event site, and usually has the Royal Pavilion as well as other pavilions around it. This area is defined by ropes, often with flags hanging off of them at a tournament.
The place where the Minister of the Lists keeps track of the paperwork necessary to actually run the lists. This is usually a spot on the tournament field, usually in a pavilion or under a sun shade.
The Lists refers to the lists (paper listings of combatants) used to run a tournament. Other uses of this term include the field on which a tournament or combat activity is taking place as in the List Field.
As capitalized, is used as a title within the SCA for those with Awards of Arms. Note that unless someone specifically does not wish to be recognized as nobility within the SCA, anyone may be called "lord" or "lady" when using the title for someone who is not armigerous, one uses it a with lower-case "L".