I started my first team in December, and I like the game so much I now have 4 of them. It has been educational. I'm already realizing that I made some pretty dumb moves at the beginning. For example, I signed this guy to a rebuilding team at $10 million per year, plus a $7M bonus:

http://whatifsports.com/HBD/Pages/Popups/PlayerProfile.aspx?pid=4607781

Question: how big of a mistake was this? Scale of 1-10? He's a solid fielder, but I'm realizing that contract was excessive.

Follow up question: do any of you veterans remember your worst rookie mistakes? Please feel free to share!

I'd give it maybe a 5 or 6 on the dumb scale.  He is a solid fielder, and gives you decent offense for a primarily defensive-oriented guy at SS.  The fact that he's a LH hitter helps, because he'll be getting around 60-65% of his AB's against RH pitching, so he doesn't get the "same handed" penalty as he would had he been a RH hitter.  Plus, he has decent speed and baserunning, so he'll steal some bases for you. 

The contract is excessive, which is why it's just slightly dumb.

My only comment to other "rookies" out there . . . get at least 2 or 3 full seasons under your belt before taking on a second, third, etc. team.  You don't want to make the same (or similar) newbie mistakes 2x, 3x or more times over with different teams.

About a 7.   I let a similar guy walk because he demanded 3.8m.   My guess is you overpaid by about 7m per year plus the bonus.

I thought Hardball Dynasty – Fantasy Baseball Sim Games - Player Profile: Sammy Mota would be awesome in my first season.   He got 137 non-descript AB while i owned the team and none after I gave it up. 

I make a dumb signing every few seasons.  Most of us do.   I just try to limit them to a lower dollar figure than 7m per.

My immediate set of mistakes was signing a few sixth-season minor league free agents. They can look good to a brand new owner because they're still relatively young, and may still show projections for improvement. Of course, I didn't realize that sixth-season status means that their original owners have realized they should never get past AAA ball, and have given up on them.

Not a lot of real harm done, but I spent a few seasons waiting for those contracts to just expire.

At least I never got trade raped. I started by looking back over the history of the franchise I was taking over, and realized that a previous owner had been boned a few times.

Overall, I would say the biggest thing that can get you in trouble at the start is not knowing/still figuring out how to properly value players... and making moves based on poor evaluations.

You overpaid, not by $7M per year, however.  He's an OK glove (only 12 + plays) and an OK bat....no harm in that at SS.  He's a $6M player, generally....IMHO.