If you're a beginning player looking for broad brush understanding of Netrunner strategy, I can't recommend highly enough the following two videos from the YouTube user Willingdone
:Evaluating Runner Play: Expected Value and the Big PicturePrinciples of Corp Deckbuilding: Winning and Defending
Netrunner is incredibly deep game with thousands of specific strategies and possibilities on each side. But there are several core principles that nearly all the different decks and strategies are built on.
Willingdone does an amazing job of boiling down the game to its essence and provides you with a set of tools for assessing the myriad decks and strategy proposals that you'll find on sites on netrunnerdb and stimhack.