I would say that the best way to start is to consider your own likes and dislikes. For flowers, grow first what you like best, if they are EASY plants. Spot things in nurseries and write their names down, so you can buy them when you're good and ready and find a sale. It's easier (but MUCH more expensive) to buy a plant than to start a seed or a cutting.
But once you develop some habits, seeds and cuttings let you grow ANYTHING, no matter how rare, almost for free.
And then you have plants and seeds to trade to other gardeners.
Then you might have to join a Twelve-Step program ...
Gardening can be ... habit-forming. Especially if you grow your own seedlings.
By all means look at neighbors' gardens and pick out plants you like (since you know they can be grown in your climate). If you see the neighbor, be sure to compliment her what-ever-it-is plant, and ask the name. Write that down and mention that you're going to look around local nurseries for one that is almost THAT nice. Maybe ask where she got it. Maybe ask if you may take a photo.
This is exactly like telling a mother that her child is beautiful, smart and far above-average! If she knows about cuttings or divisions, she may offer you a clump next time she divides the plant, or let you take a cutting and root it in water, or save you a few seed pods.
If nothing else, you'll have the name of a variety that grows in your neighborhood and that you like the looks of.
It's always classy to have something to offer back! A beginning gardener doesn't have many plants, or a basket of zucchini, but you can offer to water her beds and chase deer away when she goes on vacation. Older gardeners may really appreciate your help in carrying or digging. If you get into either seed saving, seed buying & trading, cuttings or other propagation, you can have a stash of seedlings on hand and ready to offer, trade or give away, to establish your local rep for garden-generosity.
For vegetables, grow something you like to eat, although many things are just plain bad after being shipped cross-continent and then laid on a supermarket slab for weeks. As one lady told me when I was a produce clerk: "This lettuce is DEAD!" Fresh-picked from your own garden, you might love that veggie for the first time in your life.
The advice to prepare the soil or raised beds now is good advice, but not fun. If it was early spring, I would advise picking a few of the easiest flowers just to see them grow and gain experience, but this is too late in the summer to start zinnias, marigolds or other annual flowers.
Anyway, it's never too early to chop up some turf and flip it over. Buy bags of manure/compost and dig some in.
Lay down coarse chunks of bark ("mulch") to keep weeds from sprouting, keep the soil cool and moist, prevent rain from making soil "crust" and start the never-ending process of feeding organic matter to your soil. "Feed the soil, and the soil will feed the plants". You'll also be feeding and encouraging the soil microbes that make soil different from "dirt" and keep plants healthy and well-fed. The mulch breaks down very gradually and adds its organic matter to the composted manure you just added. You'll be adding mulch over the years, as it breaks down. It is SO much easier to spread mulch every year or two, than to spend 10 times as much time weeding. It also reduces the amount of water you have to add.
Now, I love digging, so I would have said FIRST to excavate, grade, trench, double-dig, add compost and build raised beds. Add compost. Screen the soil, remove rocks and weed roots. Add compost. Lighten clay. Add the pixie dust of your choice, be it chemical fertilizer, organic fertilizer, rock dust, sand, grit, bark, coco coir or even peat moss, though that's going out of fashion as good sphagnum becomes more expensive and cheap brrown peat more common. Raise walls 6-16" high for a fancy "raised bed". Add more compost. Till. Make the Army Corps of Engineers green with envy!
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http://garden.org/thread/view_...
But if you lack mole ancestry and would rather do things the easy way, look up "lasagna gardening". They kill the grass (eventually) by laying down corrugated cardboard or multiple layers of newspaper. Then they drop a lot of compost and "stuff" on top of the paper ... and then they immediately grow right in that "stuff"! (It sounds better when you think of it as "they do some sheet composting on the surface of their raised beds, and they grow plants right IN the compost".)
Start small and only plant and do things that you enjoy (for now). If you catch the bug, soon you'll be eager to pamper your beds and follow arcane theories - do almost anything to make your plants more lush and vigorous. But the desire and pleasure should precede the craziness!
