Way to prevent rooster from being mean?

Keep socializing! Keep hand-feeding, even if he does peck hard. When they're growing like that, they have trouble knowing which end of them is which, where there feet are as opposed to their wings, and how hard they can peck at things. Just like real kids, they have a clumsy stage. :)

You'll get a ton of differing opinions on this subject. For example, my advice would be not to handle your suspected rooster. Make him give you a wide birth when you're walking around. He should know that he has to respect you. Hand feed the hens, when the little roo comes to eat shoo him away or toss him a few bits of treat. My roosters aren't cuddly, but I've never been attacked by them, and neither has anyone else. Including my children. In my opinion, a rooster will attack when it thinks he is or can be above you in the pecking order. See it the way the chicken would, you have to be the dominant rooster. If you aren't, you have to tow his line- and that can include him attempting to put you in what he thinks is your place. Good luck.

I tend to be of the handle-them opinion.  However, if a really pecky rooster expects treats from you, he will forever be running up to you and this can be a problem for very small kids, even if he is nice.  But also, he might peck their hand in expectation of treats.  Not mean, but painful and very upsetting to little ones.  Even an approaching rooster can be intimidating enough for kids, let alone one that gets too close.

 

Handle them, but if he's really pecky, do not give him treats.  Now he will approach you and allow himself to be picked up, great.  Hold him for long stretches of time.  You do not want him running up and pecking at hands and shoes.  As a mother of two little ones, trust me on this.

Pics would help people tell you whether your predicament is what you think it is.

 

Also, give this a read: http://wiki.answers.com/Q/How_do_you_stop_a_rooster_from_attacking

It's a really good summary of how we handle our rooster.  So far, it has been working and we have never had to watch our backs or defend ourselves in earnest (and our roo comes from a background of kids teasing/kicking him).  He's actually been getting much better...not spooky with us or starts getting his hackles up like he wants to start something.

 

Basically, watch his behavior AND yours.  You need to be careful not to present yourself as a threat OR a rival, so try seeing things from his perspective when you approach, handle, and are otherwise in the vicinity of the flock.  If he ever starts to get a little miffed with you (you'll know - watch his body language and those feathers), pick him up.  Pet him, talk to him, walk around with him, and when you put him down (make sure he's not struggling when you release him) give him treats.  Regularly approach him with treats so he associates you with good things.  While you can handle and touch the hens around him, AND SHOULD, don't push them to the ground patting their backs (he'll think you're mating them, which is a direct challenge in rooster speak).

 

The hardest part will be training yourself and your children.  For example, don't walk up to him bent at the waist only and stuff a handful of food in his face.  My husband took several hard, blood blister-inducing pecks to his hand when he did this.  Then he did it again, and I saw him do it, and then he turned to me like "why's he hate me???".  I said because he was lording over him and shoving his hand in his face.  Once he learned to stop a few feet away, squat down, offer food, and call to them.  Once he started doing that, no more issues.

 

So just think about how you look to them when you're doing you're own thing.  Another item to keep in mind is that children are loud, erratic and fast....and that quickly flusters the heck out of a roo.  So make sure you teach your children how they need to behave around a roo...similar to if they were being introduced to a strange dog; calm, quiet, and with slow and deliberate movements.

I'm now down to just one roo, the one who has somewhat of a biting problem. Otherwise, he's well behaved, and even enjoys cuddling close.

 

The secret, I discovered, was to refrain from any sudden movements when I close in on him. It's really solved the problem of getting drilled by that terrible beak. He's a twelve-pound Brahma, so it behooves me to be gentle with him.

 

As your young prospective roo nears puberty, he'll become even more high-strung and you need to establish your behavior, as well as his, early on, getting to know what his different behaviors mean. One approach - the domination approach - doesn't necessarily work with all roosters. This is why you need to learn what yours needs. 

 

There doesn't need to be bad roos. Behavior can be modified, but it's best to do it sooner than later.

What I see are his pointed hackle feathers.  I'm not an expert, but he looks like a cockerel to me.
 

 

Compare his legs to the pullet's. Are they longer and thicker? That would clinch the diagnosis, along with the pointy hackle feathers.