When you choose where you want to put your plants in your garden, there are multiple factors you should consider. Each type of plant has its own instructions for how it should be planted by seed. These instructions should be found on the back of the seed packet and include important information such as: the planting depth, preferred sowing time frame, amount of sunlight needed, and days to germination and harvest. When you plant by seed, it is often good practice to plant some extra seeds as some of your seeds may not germinate or sprout. If you plant extra seeds and they all sprout, then once the seedling grows to be a couple of inches tall, you want to thin the garden. Thinning is the process of weeding out the weaker seedlings to give the stronger plants more room to grow. The seed packets should have information on how many plants can grow per square foot, use this information to know how much space your plants will need.
This information is important to consider when you plant your seeds, but where you put the plants in the garden is also important. Some plants grow really well near each other, these are called companion plants. However, some plants do not grow well near each other and can cause issues such as bolting or depletion of nutrients in the soil. When you plan your garden, you should take a peek at a companion planting guide to maximize produce. It is also helpful to rotate your crops to replenish nutrients to the soil. By changing the garden bed you plant your crops in, it will give the soil time to recover from the depletion of nutrients caused by the plant growing there.
Another important factor to consider when starting your garden is how much sunlight will be available. If you are planning on making your garden close to your house, it could possibly be shaded by your house for the majority of the day. When possible, try to make your garden on a north-south axis without any big things that will cast shade on it. This way, the plants will not be shading other plants as much.
Below is a collection of planting information that I have collected from my years gardening. It is by no means complete or perfect, but it can be used as a base reference. I highly advise you to use the information printed on your seed packet as it will be more accurate to your chosen variety.