Ok, first as a new player, just kill shit and quest. Learn the game. See what it’s like to run around and do what you want.
Once you have some play time, I recommend reading this: http://classic.battle.net/diablo2exp/basics/
At that website it will tell you EVERYTHING about this game. Read and read. There are some tricks but it would be best for you to learn the game and then learn this tricks etc. thats my opinion.