Garden Woes

This is the second year that my husband and I have tried to make a go at a vegetable garden. We put out corn, beans, cucumbers, tomatoes and sunflowers. The tomatoes and beans look pathetic. The corn started tasseling out too soon. And so far no cucumbers. But the sunflowers look great! But we're not going to give up just yet! I know that we have a lot to learn about gardening. Does anyone out there have any great gardening tips? We live in the northern part of Texas and the weather can be quite unpredictable. In May we had torrential rains and wind. And now in June it's gotten really hot and no rain so far. I'm thinking that if I want some corn this year that I'm going to have to get it from our local farmer's market.