Definitely go for the squash, just don't go over board! A few zucchini plants will have you eating lots of zucchini and it can be hard to give away at the height of the season.
Greens are really easy to grow and could probably be planted now. Arugula, spinach, lettuce, and other greens (my fave is mizuna--a Japanese mustard green) like cooler temps, so they are great spring and fall crops.
Fresh herbs are super easy too. I already have mint, lemon thyme, and rosemary growing in pots. You can do herbs in the ground too, just don't put mint in the ground, it spreads like a weed.
If you like it, okra should grow well in your area. I have never tried it though, so I'm not sure how easy it is.
Tomatoes can be temperamental, so you might want to check out a gardening book at the library. They are so worth the effort! Nothing tastes like a garden ripe tomato still warm from the sun (I'm drooling!)
Green beans are also super easy to grow. The just need some thing to grow up. I like to make a "teepee" using bamboo stakes (the longer the better--at least 6 feet long.) You stick them in the ground and then tie them together at the top. Then you plant one or two bean plants (or seeds) at the base of each stake. At first you need to "train" them by wrapping them up the stake, but once they get started they'll do the rest. I love to eat fresh green beans raw straight off the vine. Yum!
I'm starting several seeds right now. I have 4 kinds of tomatoes, two kinds of basil (Italian and Thai), cilantro, jalapenos, parsley, and sweet Italian peppers. I'm going to start some NM chile peppers too, I just need to find the seeds. Greens and squash I'll start outside soon. I love spring, I can't wait until I have something I can actually eat!