THE VEGETABLE GARDEN PLANS
You really need to know WHERE the vegetables are going to be put. Once you know that, THEN you can get the soil sample! The reason you should deal with this now is that once the plot is situated you can begin to prepare it so it's ready next spring when you are ready to plant things there. You'll have spent a fair amount of time during those winter months planning what seeds to buy; now you need to know where to put them! Go to this veggie link for a more complete "walk through" for the what, where and hows, etc. of vegetable gardening.
So, PICK YOUR SPOT! Then, IF you can, rent a roto-tiller. Maybe you're lucky and you already have one of those in the tool shed, garage, or barn. Roto-till that plot, first one way, and then the other until it's soft and about 6-8 inches deep. You can take out the grass or weed "clumps" and toss them into the compost, or you can leave them right were they fall. However, if you leave them, they will start to grow once again. This is another reason to begin to plan this garden now.
One of the things that I have found works VERY well killing all that green stuff you dug up, is PLASTIC. Depending on the size of the garden, you can cover it wih black plastic, weigh it down and just leave it for the rest of the season. In fact, right up to next spring if that's possible. The plastic will cook the grass with it's seed and turn it into compost right there in your garden! How much easier (and better) could it be???
In the spring, after the plastic is removed, you can amend the soil with the goodies the Extension Service suggested as a result of the soil test. Dig that in, Rake it out. Plant the seeds!