How do you use and edit b-roll?

I create advice/inspirational videos for students on YouTube. When I go to university I take my camera and record some footage of the university and people studying. Out of every 60 seconds of footage I record, I only keep about 30 seconds of it to use as b-roll for my videos and keep them down to short 3-5 second clips. I've collected quite a lot of footage, but what is the best way of storing it. Is there an easy way of having the b-roll already loaded onto Adobe Premiere Pro, so when I'm editing my a-roll and want to quickly add in some b-roll, I don't need to open up the full 60 second clips and edit them back down again?

I'm not sure if I've explained myself very well. But any questions welcome, and thank you in advance!