The first place to look for plants is the local nursery. You can check different nurseries in your area and inquire about jasmine directly. Ask about whether the plants shown are deciduous or evergreen and get details about the bloom time and type. Many nurseries have master gardeners on hand who can help you discern the quality of the available plants as well as provide some basic growing tips.
Native jasmine can be found in India, Iran and other Asian countries as well as Africa and Australia, parts of Europe and the United States. If you plan to dig up the plant, be sure you know the local laws and regulations as they may limit areas and particular plant varieties. In places like Georgia, South Carolina, Alabama, Mississippi and Florida, jasmine is readily available and frequently pops up in the wild pine forests as well as yards and shops. Be careful with plants such as the yellow-blossomed Carolina jessamine (jasmine). Unlike honeysuckle, these flowers are poisonous -- don't eat them.
Numerous jasmine sources are available online. Many of the companies offer an 800 number if you prefer to speak with someone directly about plant options. If you look at images of the plants and flowers in advance, you can make a list of questions to have handy when you're on the phone with or emailing a representative.
An often overlooked possibility for getting starter plants could be right beyond your fence or down the street. If you know of someone who grows jasmine or smell the delicious fragrance while having an evening stroll, dare to make the acquaintance of the growers if you don't already know them. Sometimes jasmine grows prolifically and the grower will yank out clumps of vines. Simply indicate your interest in owning some of the plants that would otherwise go into the trash can or compost pit. Most neighbors are happy to comply when they reduce or trim back plants.