It is an easy herb to grow, but as it takes a while to germinate from seed, best to buy a plant for starters. It dies down during the winter, but soon pops up again. You can also take cuttings in the Autumn to increase your stock.
Yes but be careful, the plant just goes 'mental' in the summer, so I would plant it in a container if I were you....unless you'd like your garden resembling a Lemon Balm Farm.