Actually, my brother got me started. He had lived in New York City (because of his work) for years and hated being in the city. He finally rented a townhouse, where he had access to the backyard, and he started a garden. He had no idea what to do, he just bought a flat of flowers and a trowel and went to work. I was lucky that he passed on his enthusiasm to me.
When getting started with gardening, the best place to start is your local nursery. Go to an actual nursery, not somewhere like Lowe's or Home Depot. They will know your growing conditions best and are knowledgeable about what things grow best/easiest in your area. I've found that they are a font of knowledge and can save you a lot of headaches and help with planning your garden.
For flower gardening, you'll probably want a mixture of annuals (plants that die each year) and perennials (ones that come back each year). Annuals usually bloom all season, whereas perennials have a much shorter bloom time (so make sure you choose perennials with varied blooming times). Again, your local nursery can help with selection.
For vegetables, you'll want to find a sunny area, as most veggies want full sun.
Having said all this, the best thing is to just do it. You'll learn quickly what works and what doesn't. Good luck and have fun!
