The best knowledge will be gained by reading through the forums.
And...
Start off with one team and learn as much as you can with that league before moving on to others and getting overwhelmed. Figure out what is important to you in regards to specific skills for each position (and develop a custom weights system).
Learn each aspect of gameplanning a little at a time. Don't think you have to learn it all at once.
For example, maybe you want to start by picking your own set of plays for offense and defense, and then "load recommended" for the rest. Then add in a new aspect as you become more familiar with them, etc.
And don't be afraid to ask questions. There are a lot of items that seem pretty obvious to us that have been here for a while, but they are probably not so obvious to a new player.
Welcome, and enjoy!
