In a small garden it makes sense to plant some: lettuce (iceberg and butter), beans, peas, carrots, potatoes, a couple tomato plants, onions from the bulb (not the seed) and strawberries.  The vine veggies take up too much room for smaller 4ft by 4ft plots. I would only plant vine veggies  vertically or if the garden is at least 8ft long due to experience. Each person enjoys different veggies for a snack. Most youth like: carrots, peas, strawberries, cherry tomatoes and potatoes to make fresh home fries.

Every Dollarama has a seed cup incubator which is a 16in wide by 24in long plastic greenhouse with moss cups in it $7.  Purchase the seeds specifically like: carrots, lettuce in the packs. Potatoes and onions should be purchased in the bulbs not the seeds!  Tomatoes and vine plants should be purchased for $4 to $6 at a local Home Depot or Plant Supplier like Potters etc. The seed packs and incubator are typically around $4 to $6 a piece.  So for a small plot (4ft by 4ft) the budget should be around $25 maximum.
Follow the directions on the seed greenhouse and plant 2 seeds in each cup then water, put the top clear top on and each 3 days just soak the bottom as the roots will grow throughout the cup.  When the plants are touching the top of the greenhouse simply take it off and let them grow another 7 to 10 days.
This means that this first step needs to be seeded around March 15 to April 1, planting should be around April 15 to May 1 time frame. 
For beans, peas and tomato plants there is a green mesh $4 and $3 bamboo sticks (48inches) that you can purchase so you plant these at the back of the garden as they will be the tallest and will grow up the green mesh. 
NOTE: if you want lettuce for the whole season then seed 4 plants first, then 10 days later seed another 4, then 10 days later seed more..this will give you in 60 days enough lettuce to last a month without it all maturing at once!

Find an area that faces south to meet the sun during the Spring to Fall months.  The garden plot only needs: sunlight, a black weed cloth (4ft by 4ft) - Kodiak and Meadow have this resource already, soil about 6 inches thick put below the weed cloth.  Then when planting cut holes in the weed cloth and plant the plants..then weeding takes about 1 min a week when the plot is set up this way.  Follow directions on the packages.  The actual planting should take place between April 15 and May 1st. Remember to stagger seed your lettuce so it matures at different rates to spread it out.

Managers should sit the youth down in March and tell them that the resource is planting a small garden. Which veggies (from the list above) do they like the most. Then with youth purchase the materials as suggested above.
Youth needs to understand that this is a fun activity but it is really a skill meaning that at any time they can simply grow their own food or some of it.  This is great because the Kodiak youth started to pick his own produce for snacks when hungry instead of grabbing chips or cookies etc.
Finally the youth will need to weed once a week. Weeding should be minimal as the black weed cloth will eliminate 99% of any weeds!  The most important task during the days when the temperature is above 24C is to water the garden at low sun (am or pm). Never water in direct sunlight as the water magnifies the suns rays to burn the plant effectively decreasing its ability to create.
These simple chores for the garden should be added to the weekly allowance as it will only take a few minutes a week to ensure the maintenance is effective.j
NOTE: Cherry tomatoes, once the stalk is 12 inches high cut the very bottom branches off with scissors. When the tops grow there is a shoot or runner in the middle of two branches, simply pinch those off.  By doing this as the plant grows we funnel the nutrients into the areas to ensure proper fruit growth or yield. Youtube Search (how to care for cherry tomatoes).

On the seed packets it tells when the harvest should occur.  Simply grab some tomatoes off the stem, some beans or peas off their vines, when the potato plant tops start to die in the fall, dig them up, the carrots just pull out, wash and enjoy.