If you just want to assume good soil and take the plunge, all you have to do is prep the garden in spring so that there's a smooth, clean surface for seeding, for example, by lightly rototilling, then raking.
For a more thorough start, you should consider the soil composition and fertility, and what sort of weeds you can expect.
*fertility: You may want to test for nutrients, the basic is NPK, also pH. You could get a home kit and DYI, or send a soil sample to a lab (costs about $20 here) for a more complete analysis. If you're on a farm, you could ask nearby farmers about the land you're on, if there are local conditions that affect veggies. If it turns out that there are deficiencies and you want to add stuff, depending on what it is, it may be best to incorporate in fall or in spring. For example, if you are able to add manure of some sort, that should go in in fall.
*soil composition: You may want to improve the soil. For a quick test to get an idea of what kind of soil you have, compress a handful soil in to a ball; if you can make it hard and solid, you have a heavy, clayey soil (poor drainage, hard for roots to penetrate), if it more or less falls apart, you have a really sandy soil (doesn't hold nutrients or moisture well)–in both cases, you want to add lots of compost. Somewhere in between and it's probably OK. Depending on what you're adding, it could go in in fall or spring.
*weeds: It's a good idea to ID the weeds that you cut down and tilled in. If you had something quite invasive, you should know. In an extreme case, like, say there was quackgrass that you just chopped up, you'll have a big problem as it'll grow back like crazy. In any case, it's a good idea to be familiar with your weeds, as there will be weed seed in your soil, waiting to germinate. If there's nothing too dire, it's still cool to know what to expect and read up a bit.
It's not clear whether you're starting a backyard garden or a plot in a field, and what size it is. Wherever it is, there are location considerations. It sounds like you've already picked your spot. Did you consider location for things like sunlight, slope, windbreaks, drainage? Relatively minor location adjustments when you're starting can make a big difference once your garden is established.
The easiest thing is to have someone with growing expertise drop by and check things out. It's always easiest to do things first-hand. Then you can follow up with books and web sites for details (there's LOTS of great info online, like this excellent page: Get to know your soil).
Or you could charge in. One way or another, you'll tend to learn by experience, just depends on how much you want to hedge your bets upfront.
I'm no EXPERT on new garden start-up, but these basics should at least help!