Study, study, study. ESPN's top 200 is a good starting point for cheatsheets. You can view some mocks there in progress.
I've always kind of had a disdain for participating in mock drafts, but doing them (or looking at several) will give you some good insight to where players are going.
Have a plan after you know what pick you have. If it's top 3, you are set with A-Rod, Soriano, or Pujols. After that, it gets a little tougher. I like grabbing hitters, or the ELITE SP's like Prior, Pedro (around 6-10) or if you grab a hitter first round grab a Schilling or Johnson (Schil should be solid, Randy is getting old...but I can't pass him up mid to late 2nd round).
DON'T stock up on pitching early. Take 2 SP's in the first 4-5 rounds, then grab hitters. It seems to me that more unknown pitchers contribute than unknown hitters. Last year I grabbed Willis and Webb. Gil Meche would have been a boost to any squad. Hitters are more predictable IMO. Stock up on them, anchor your SP with a couple SP's in the first 4-5 rounds.
Last year I targeted Prior as my first SP to select and took him at the end of the 3rd round. I waited until only one of my top-shelf SP's remained before taking him in the 6th round (Halladay). Yeah I got a little lucky that they both had huge years, but I planned my work and worked my plan. It paid off. I don't think I grabbed another SP until about round 10 or so, when I grabbed Woody Williams. Again some luck involved, some work - Woody had been a stud as a Card and I drafted him on that basis. Waiting on all these SP's allowed me to grab Pujols (stud), Berkman (good, not great year), Sheffield.
I had some bad picks...AJ Burnett for one, but finding SP's on the wire over the course of the year is not too difficult. Grab the young gun that impresses of the free agent pool early - don't be afraid to dump that late round stiff you had hopes for.
* Steroid induced record