Determine which plants you want to grow from seeds, and which plants you'll purchase already potted. Sketch out a plan for your garden and determine how many of each plant you need. Take into consideration how the sun rises and sets in respect to your garden and be sure to plan accordingly. Some plants will require more sun than others. As well, be sure to take into consideration the anticipated size that the plants will grow to, and avoid blocking the sun from smaller plants with larger plants. You'll need to space your plants appropriately. Some plants require more growing room for roots then others. Most nursery plants and seed packs will provide instructions for this. Be sure to account for this in your sketch.