You're clearly Intelligent and Insightful, Brother Marin, so if you get drawn in to the Obsession level that consumes Brothers Manx, Mayo, and myself, I have no doubt that you'll get very good at it, and quite possibly far faster than you'd expect. It is quite akin to learning a new Language.
I can assure you that I haven't the faintest clue what I'm doing, but the Pursuit of Knowledge is a deliriously exciting one. There's always more to learn, and the Process is wonderfully rewarding.
01 ~ I agree with both Mayo and Manx that
Draft BreakDown is a tremendous Resource. I watch Hours and Hours and Hours of their stuff, often over and over and over. Every Snap is a potential Treasure Trove of Clues to numerous Aspects of each Prospect's Potential!!
02 ~
NoonKick is my second favorite Resource. Unlike Draft BreakDown, they don't break down individual Prospects, so you've gotta do some serious trolling to get any Scouting done...But they show entire Games, which is pretty cool, and they're not shy about digging deep into the College FootBall Wilderness and giving you Tape of some pretty obscure Prospects, which is pretty awesome!!
03 ~ I also agree that it's wise to CrossCheck your Impressions against those of guys who've been doing this a lot longer and have seasoned eyes. They can help you ~ they've certainly helped me ~ develop a better sense of what to look for in lo a thousand little ways as you develop your Craft.