Here is a list of all Professions in Civilization IV: Colonization .
Any colonist can perform any profession, however an expert or master will be much more productive.
Resource collection [ ]
Profession
Role
Cotton Planter
Can harvest cotton from surrounding tiles
Farmer
Can harvest food from surrounding land tiles
Fisherman
Can collect food from surrounding sea tiles
Fur Trapper
Can collect furs from surrounding tiles
Lumberjack
Can collect lumber from surrounding tiles
Ore Miner
Can mine ore from surrounding tiles
Silver Miner
Can mine silver from surrounding tiles
Sugar Planter
Can collect sugar from surrounding tiles
Tobacco Planter
Can harvest tobacco from surrounding tiles
Production buildings [ ]
Military/Service (Units) [ ]
Profession
Role
Armed Brave
Available only to natives, a native can become an armed soldier
Armed Mounted Brave
Available only to natives, a native can become an armed soldier on horseback
Brave
Available only to natives, serves as the default land unit
Colonist
An unspecialized, defense-only unit
Dragoon
Serves as the default mounted unit
Missionary
Can establish missions in native settlements
Mounted Brave
Available only to natives, a native can become a mounted unit
Pioneer
Can improve the surrounding lands
Scout
Can explore surrounding lands on horseback
Soldier
Serves as the default footsoldier