FF it to the timestamp (place) you want to start your clip, press "start select"
Once you do that you have two options - you can let it play out to the timestamp you want to end or you can drag the film slider to that timestamp - then press "end select."
Now that both start and end points have been selected, press "copy select" - you're done.
The clip will be saved with a copy name of original filename. You can, of course, rename the clip to something new.
<edit: it can get wonky if you try to manually input the start/end timestamps.>