For starters, I would familiarize yourself really quickly with who the starters are with every team. Nearly any fantasy baseball website has complete roster depth charts for each major league team. I use CBS Sports' personally but some prefer MLB.com's or ESPN's--any accredited site will suffice. I'm assuming you are in a traditional roster size league (14 hitters, 9 pitchers) which means you will need to be familiar with at least the top 224 hitters and top 144 pitchers. Going even deeper than that can only help though as you may find a player with better breakout potential or keeper value depending on your own preferences.
Since you will be participating in an auction draft there are a few important things to consider:
1) Prepare your cheat sheet (tiers, dollar values, stat lines) --This will allow you to easily track what teams get what players throughout the course of the draft and when you may need to bite the bullet and pay for the last guy in a tier if there is a big dropoff.
2) Create a spending plan (budget) --By breaking down where you want to spend your payroll you can easily slot players and actively keep track of how much money you have available throughout the course of the draft. This goes hand in hand with your draft strategy.
3) Go in with a plan but be flexible --You can either google or I'd direct you to this article http://sports.espn.go.com/fantasy/baseb ... 0manifesto
by Matthew Berry for some really basic spending strategies and overall advice on auctions.
As I mentioned above, flexibility is key because depending on how your auction progresses you will need to adjust your strategy accordingly. Also, if this is a brand new dynasty league then focus on drafting a more balanced team that will perform well now and in the future. However, if you are joining an ongoing league I would recommend focusing in on getting cornerstone players and taking chances on acquiring excellent keepers since your opponents will be operating from a position of strength having been able to accumulate keeper value over the past few years. The ultimate goal in a dynstasy league is to acquire the most value (in the form of players' statistics) for the minimum amount (in the form of low $ contracts). Pair these guys with studs and you have a winning combination.
Best of luck!