Here is a video that will take about an hour of your time. This video goes fairly in depth about the adc role. How to farm, how to harrass, how to team fight, how/what to expect from your support, what your support should expect from you, etc. If you want some credibility as to why you should spend an hour of your life watching this video, the dude that made this series ended up getting an internship at riot :P
https://youtube.com/watch?list=PL9RdXhXESRJz4Z_mPEizexEeqXcTIylzN&v=1oPLc6DZvz8
Keep in mind, the series is a bit old. So some things are outdated like the odd item he'll mention that doesn't exist anymore, or the champion skill that's been reworked and doesn't work how he says. The key things you'll take away from any video in the series is the core mechanics.
If you decide to watch it, at the very least take mental notes on things you know you don't do or can improve on either in frequency or consistency. Writing things down would be better, or revisiting sections later. Don't try and master everything you see in your next game. That's a mental concentration overload. Isolate one to three things you REALLY feel is your weakness, and work on those things. Still be aware of what you aren't going to concentrate on yet. nothing says you can't try to improve everything else at the same time, just keep in mind that those are not your current goal, so don't beat yourself up when you screw them up. And don't let it take away from your current goals. You'll come back to it later and really work on it then. When you're comfortable with those few things you chose, look at your notes. pick something else and revisit that section of the video. work on a few more while still maintaining the initial set of improvements.