Summarized/based on the rules from 1e Twilight: 2000...
Foraging:
In a 4hr period, a character may search a 1km (or 1mile, your choice) square area. For ease of use, consider an area “foraged out†after one attempt.
Only one foraging party may forage an area. The number of people involved reduces the amount of time it takes but does not increase the amount of food found. Two people halve the time for example. Foraging an area is a Medium maneuver performed by the character with the highest foraging skill. Results on the moving maneuver chart indicate the percentage of food found.
Fields: Characters do not forage, per se, in fields, and no die roll is necessary. In winter & spring, there is no food to be found in fields. In the summer and fall, there will generally be standing crops and characters can gather virtually as much food as they can carry. In one period, this will generally amount to 200lbs per person. An additional 4hr period is required to separate the food from the inedible parts. This will yield a total of 50lbs of edible food in the summer or 100lbs in the fall. Alternatively, a 4hr period can be divided into 2hrs of gathering and 2hrs of separating for half the numbers above.
Fishing:
In a 4hr period, a character can catch enough fish to produce the amount of edible meat found on the Foraging/Fishing table. Fishing is a Medium maneuver with proper equipment (line and hooks, net, etc) or a Very Hard maneuver without. Double the totals for net fishing from a boat in large open waters (large lakes or the ocean).
The table below summarizes the food output from foraging on a successful roll:
Foraging Table (in pounds)
Winter Spring Summer Fall
Wood/Scrub 1 3 5 6
Meadow/Swamp 0 1 2 2
Field 0 0 50 100
Fishing (1D6 times) .5 2 1 1