If you can, mow/rotary cut it off so there aren't any really tall weeds/grass, I'd do that first. Then plow everything under. If the soil isn't too damp, then I'd till it about 3 times. That's how we do our garden (plow, then use tiller attachment for tractor). I went over ours 3 times with the tiller after it was plowed and it turns the soil into a nice fine bed great for planting. If you don't have a tiller attachment, use a disk and run over it until you get it as smooth/fine as you want.
Oh by the way, you could use the fork in your kitchen drawer to turn the soil in your garden, but of course that would take awhile /forums/images/graemlins/smile.gif My point is, there's more than one way to 'skin a cat'. No one way is perfect or the absolute correct way. It really depends on what you're after and what your soil conditions are (heavy clay, sandy, nice loam, etc). I could have a really nice garden tilled up and ready to plant with nothing more than a tractor mounted tiller. Sure it would take a few more passes, but it pretty much gives the same results as plowing and then tilling. It's much easier to plow everything under and then till though. You can usually get a little deeper with plowing and then tilling also.
As far as the tines being smaller on a lesser brand tiller, that's ok as long as you're not being rough on it. For example, I've already hit several nice rocks and roots with our John Deere 655 tiller. But the tines on it are big and tough so it just spits out the rocks like nothing and I can't see any visible damage. Not something I like doing though. Just use some common sense. If you have a really rough area and you intend to only use a tiller without plowing or you have rocks, etc...go easy on it.