First, Lots of farms and farmers isn't necessarily the best thing to do. You always plant one seed, but the greater a dwarf's skill the planter has, the more plants are harvested. The trick is to turn plant gathering off for all dwarves, except your starting grower. He get's to plant and grow, even if you have other food sources. I generally set up my farms to be 3x3 rooms arranged around another 3x3 room with a seeds stockpile(no barrels, just bags). Set up two of these nodes, and you've got plenty of farming for dwarves. Two growers work wonders.
Turn off cooking for plump helmets. Set up a full time brewing operation. There is no such thing as too much beer. Never. You can never, ever have enough. That should eat your supplies quite well. Protect your planters: their skill is going to be slowly acquired, and it's invaluable for giving you a source of food that will be available even if you are cut off from the outside world by something horrible. HORRIBLE.
Trade for food. It's awesome. If you can make it to the first caravan, you're ok. Make a bunch of wooden screws or spiked balls. Sell them. Sell stone spiked balls to the elves. Buy their ingredients. Cook it all up into LOAF and serve it to those mewling dregs. You should be able to import most of your food, and be able to stockpile large amounts. Requires you to trade.
I think the posters about Turkeys are spot on. They spit out eggs, and eggs are great for keeping your dwarves fed. Actually breeding them gets a little annoying, but given the return on the eggs, it's not a bad idea to set up some side pens where you can put a hen and let her incubate dem eggs. The leather and meat thing is a side deal.
Oh yeah, buy and slaughter animals. They are delicious. And you get free cages! whatever, just butcher'em and profit. Also, you need to have bones incase a dwarf get's that gleam in his eye and wants to make something. Whatever, it's food.
Have good cooks. They make more food out of the ingredients. Lavish meals will eat up your stocks unless you have great cooks.
MY rough rule of thumb is atleast 10x as much food as you have dwarves. 7 dwarves need 70 meals. Unprepared food needs to be about twice that number. Booze needs to be atleast 20x dwarves. And keep in mind, wee dwarves need their booze too!