(Warning : Wall of Text that slightly goes deeper then the actual topic)
Although I am one who has played Fantasy hockey for only 2 years now, I'd have to say I was more interested then that before hand.
Being a huge fan of hockey slowly got my parents into getting me a yearly subscription to The Hockey News (which ultimately made me discover dobber and aftarwards, this website). I started reading some the magazines every week and then online articles. And then the yearbooks with all the stats (and me being a math junkie) and then decided to get into fantasy hockey.
This led me to a solid database of about a few years worth of stats, knowledge of stats from around the league. I find the best research is not done within an hour, but if done over a steady period of time. I read some topics over here everyday, read snippits every now and then on players I had never heard of before, watch a ton of (Leaf) games so I get an understanding of how some players play, etc.
Now, all this means is that you can't just sit down for 12 hours straight infront of a computer and know everything about a player. Information changes as more variables are changed into more concise information. Reading over time gives you perspectives that evolve over time, so the hot topics of today (say, Karlsson, Skinner to use examples) are either based or baseless. Now, this website has a great community who like to help each other and as such, can help you gain a lot of information that would require a bit of searching availible right in front of you.
I consider myself a good GM for fantasy purposes, btu that comes over time. Theory is one thing : stats are just that, a recording of what has happened. No one can accurately predict what will happen for everyone : if you get even 5 player's right you're pretty good. You can read as much as you want, but applying theory into practice is something most scientists also know isn't as easy as it sounds. Things happen, you underestimate/overestimate/forget another factor. You can research all you want, but if all your team hit injuries, you can't do anything. Luck also plays a part.
In the end, research is only one tool in the shed to prepare yourself for all the intangibles and variables that come in fantasy (and real) hockey. Things will happen, but the only thing you can to is to be prepared, and to act as soon as something that changes the whole scheme of things hit. But being the most prepared will give you the ability to know what you're doing (or at least think you know) so that when the time comes, you'll know what to do. Take the knowledge over time, and learn how to apply it (no one can teach that you know : each league is different, each manager is different, etc).
16 Team H2H - Dynasty
Start 3 C/LW/RW each, 5 D, 1 Util, 2 G (IR)
C - Berglund, Little, Ott
LW - EKane, Foligno, Kulemin
RW - Kessel, Backes
D - Weber, Green, Yandle, Meszaros, Voynob, Spurgeon, Stralman, Beauch
G - Lundqvist, Rask
Farm : Markstrom, MikGranlund, Tatar, Brodin, Orlov, Merrill, Stalock, Kabanov, Moore