Fantasy baseball is a lot more accessible than it was in years past. Every fantasy site has player rankings that a novice can use to get started. Back in the "old days," over a decade ago, we had to rank our own fantasy players. It was not as difficult as it sounds though, when you got to round 18, you could have used the help of a computer ranking.
Each player's draft value has a lot to do with the position he plays. Any newbie can intuitively grasp that concept. Many major league teams start catchers or shortstops that couldn't hit water if they fell out of a boat. However, none of those teams would tolerate poor production at a less important defensive position, such as first base. As you would expect, the deepest fantasy positions are first base and the outfield. It explains why
Some positions are top-heavy. They have a small number of elite performers, and then the talent pool thins appreciably. On Sports Grumblings we advocate establishing tiers before a draft. For each position, there should be several players that you would be happy to acquire in the draft. Print your draft list for the position then take out a red pen and draw a line between the last guy in that top tier and the first guy in the next tier. You should also establish a second tier since you will have to make some compromises and a third tier for bench players. Tier 4? That's the "do not draft" list.
I define the talent pool of a position as shallow if my top tier can be counted on the fingers of one hand. By my criteria there are three deep fantasy positions and five shallow ones though one of those positions may surprise you. Your top tier may be longer or shorter than mine and it may have different names on it. Differences aside, tiering is part of any sophisticated draft strategy. The message here is to prepare your tiers before the draft. It's a matter of setting priorities when you have time, without the pressure of a ticking draft clock.