While it is convenient to buy avocados from the local supermarket, you can also start investing in the long-term goal of having free avocados coming from your own backyard by growing an avocado tree straight from the pit.
To get started, remove the seed from the avocado fruit, being careful to remove all the fruit from the pit. Then poke three toothpicks into the pit and suspend the pit over a glass of water so that roots & a stem can start growing over the span of a few weeks.
Once you transfer the seedling into a pot equipped with drainage holes and a proper soil mix like MahaGro Potting Mix you may want to consider grafting a tree bud from a "producer" tree (an avocado tree that already bears edible fruit) onto the plant. As it is difficult for an avocado tree grown from the pit to produce fruit on its own, this process ensures that your plant will eventually grow into a tree that bears fruit.
Read more below for the rest of the process. Click on image to enlarge.