When establishing farming, I dig (at least) two 11x11 rooms. Into each of these, I place a set of four 2x10 farm plots, separated by a single tile. I use one set for underground farm plants, and the other is excavated to the surface and the ceiling rebuilt to support underground growing of surface plants. Typically, I end up with far more than I need because of the scale of this farming operation, so I tailor the outputs to match current demands. (Rope reeds for cloth, pods for syrup, quarry bushes for roast preparation, wheat for flour, helmets because we're talking about dwarves.)
For example, once I've run four plots of rope reeds for six-ish seasons, I've got more than enough rope reeds to process, weave and sew into cloth items, so I switch the farm to producing sun berries, or longland grass, or fisher berries, etc. If I find I've got too much in my plant stockpiles, I shut down farming production, switch dedicated planters to processors/brewers/cooks, brew/cook/process down the remaining plant stockpiles. The net result is a couple thousand prepared meals and servings of booze, many rows of bins full of cloth, emergency food stores full of syrup and flour that I haven't tapped, an empty plant stockpile, and farm plots waiting for me to convert them back to use.
When I did this on my last farm, I had a thousand servings of dwarven syrup, two-thousand servings of booze (mostly sunshine), and nearly two-thousand prepared meals. This is enough to keep 250 dwarves fed for a year, and boozed for half a year, before we consider syrup/flour stockpiles or additional food/booze production during that timeframe. I had only 58 dwarves when I cut off production and assigned them to 'useful' tasks. This production was managed with four growers, only one of whom began with any significant skill.
My general recommendation is to note that dwarves need 2 meals and 4 drinks per season. Once farming stabilizes (eg, around your first wave of migrants) try to keep a year's supply stockpiled, so that you have time to start production back up (plant-harvest-brew, at least a season's worth of delay) without crashing. Setting aside some dwarven syrup and flour (plant extract stockpile, kitchen set NOT to cook) will ensure that you have ample supplies of food backlogged even once your plants are dealt with. If you opt for the "feast-or-famine" method of farming, figure out what you want your farmers doing in the off season - I usually have mine get to dabbling in weaponsmithing/armorsmithing, and then spend their time handling furnace operation, pump operation, wood burning, sand collection, etc.