Hitters first. Drafting a pitcher before the 3rd round in most leagues can be deadly. This is reflected by most top 50 boards which usually have only around 5 pitchers in the top 50. A great example of this is here.
. Because pitchers only go once every 5 days, the depth of your pitching staff is important. Especially in daily roster changes leagues. Also, because every team has 5 starting pitchers, there is much more depth at the position than any offensive positions.