Chipotles are dried, smoked jalapeños; they have a sweet, smoky flavor.
Chipotle chile powder can substitue in some recipes as well as a chipotle in adobo, rinsed of the adobo sauce.
The best dried chiles are the ones that have been sun-dried and not commercially oven-dried, which can make them bitter. Look for whole, not broken pods, with a uniform color. They should be be tough but still a little flexible.
Pull off or cut off the stems and dump out the seeds. Dried chiles can be crumbled or ground and added right to a dish. Or toast them lightly in a little hot oil to intensify their flavor. If puréeing dried chiles for sauce, rehydrate them first by soaking them (toasted or untoasted) in boiling water for a half hour or so.
Dried chiles will keep for months in a cool, dry place, though they may become more brittle over time.