Which model? There can be some difference. Also, have you RTFM yet?
Sounds like you've got a variety of "micrometer" torque wrench (you turn a collar or the grip on the handle to set it, and it will "click" in your hand when you get there,) and they are rather easy to use. Between those scales you see, there should be a vertical line (runs along the length of the shaft) that is the indicator for the collar markings - which gets you in between the marked graduations on the shaft. So if you want to get, say, 22 pound-feet; you'd turn it to "20" then two marks on the handle past that to get 22.
Conversion from pound-inches to pound-feet is a simple factor of twelve - 12 pound-inches = 1 pound-foot (when I give torque specs, values under 20 pound-feet/240 pound-inches I usually give in both measures.)
Ideally, you want to use a torque wrench near the middle of its range.
We can probably give you more information once we know more about the wrench you have, just to handle specifics. But, you'll find the micrometer-style wrench easy to use, once you get used to it.