The best way to manage a garden is to have a plan for your current growing season, as well as a record of your past seasons. (I say "growing season" instead of "year" because Texas has two separate growing seasons - with different crops, obviously - but we can grow food all year 'round if we want to.
I use Microsoft PowerPoint™ as my tool to do both jobs, planning and recording. First I drew a scale map of the front and back yards, then placed the gardens, trees, and other growing areas onto it. That became my master garden diagram. [This is one of the things I can and will do for you: create a master garden diagram of your yard that you can store on your computer and then use as the basis for your seasonal plans.]
Each growing season I make a copy of that master file, label it for the current season, and add my planned crops for that season to it. I look back on the diagrams for the past couple of years, and decide where I want to put each crop, making sure not to grow the same crop in the same land more often than every two or three years.
If you need some help using PowerPoint, I'll be glad to teach you how it works, so you can keep your own set of records of your gardens across the years. Why do you want to do that? Mainly, as I said above, it helps you rotate your crops. Each plant takes a specific set of nutrients out of the soil, and each plant puts some back in. You don't want to deplete your soil of any nutrient, which would happen if you plant the same crop in the same place year after year (that's called "monoculture" - and sadly, that's the way they do it out in the world of commercial farming).
The PowerPoint file for the current growing season is also a great place to make notes about what worked and what didn't. A garden is an agronomy experiment, but one with a one-year turnaround on your experiments. One year, for example, I discovered that one particular place in my garden doesn't let cantaloupe seeds germinate. (This fall I learned that green beans grow there just fine; whew!) I haven't the slightest idea why, but I'll never plant cantaloupes there again - because I've recorded that problem on that summer's plan/history sheet.
You can see this season's plan sheet for my front yard on the Front-Yard Gardens page, and the plan sheet for my back yard on the Back-Yard Gardens page.
I want to express my special gratitude to my gardening mentor,
Christine Eubank,
who showed me how to plan - and plant - a good garden.