Get a gun. No, I'm serious. Okay, maybe a little too serious. Honestly, a gun may help though. Onto the point, if you're really serious about dedicating yourself to entertaining children, you have to understand it's harder than you think it is, and crazier than you will ever imagine. Think of the worse thing that you can possibly pull off when you're trying to perform; you flash, you perform a bad sleight, your gimmick isn't working, it makes a noise, heck your shoes are untied. Kids will catch onto that faster than flash paper next to a pyromaniac. I'm not trying to scare you, but I was scared plenty performing for kids myself.
All I'm saying is, you have to know what you're doing. The worse thing you can ever do is walk into a show, holding a sliver of doubt of whether or not you'll be able to perform your next "trick." I say trick because, a trick is just a trick. You can poke at it, lick it, etc, and it'll still be a trick. So, turn it into your act of magic. Tell a story, make a joke, you can make a play if you want, just know the lines, study them, breath them, eat them, and live them if you catch my drift.
Control those kids. They're rowdy, they're crazy, they can be worse than drunk people on the streets, performing at 12:00 AM on New Orleans, during Mardi Gras. Trust me on this one, I've done it. I'm not implying that you should use rope and duct tape, although that would be a blessing, just learn a method to get them to be quiet when the moment counts, to sit down when you need the proper angles, and to maintain their attention like bugs to a zap light.
Last, but certainly not least, keep it short. I cannot stretch how important this is. I'm pretty sure Paddy has type that line at least a million times. Kids are kids. There is nothing you can change about that. Their attention span works like... Well, I wouldn't know how it works, otherwise I'd be the next David Copperfield for children. Anyways, they'll get bored if you drag it along. Once they get bored, prepare to be overthrown like the the tyrant you are for taking away their precious time.
So, the conclusion is, you need to have a theme, a story, some form of patter to keep them hook, line and sinker. You need to learn crowd control, whether it's the streets, or a living room, you have to keep them in order. Also, keep it short. Make the content as great as you possibly can. Leave them wanting for more, let them crave for more wonders instead of drowning them in it.