Thankfully, there is sooo much great information from the working pros around here and on the cafe. I've spent countless hours (to my wife's chagrin) researching what the experts have to say and putting together a character and show.
Then I see someone post on these forums say "someone asked me to do a kids magic show next week and here are the 10 card tricks I'm going to do. Oh, and I've got this really great body mutiliation trick where I saw off my finger!" Yeah, the little tykes are going to love that one!
I've entertained kids in non magical situations for years as well a pulling out the occasional magic trick and I learned it's not as easy as rambling through some card tricks.
I had a show almost completely scripted, practiced and rehearsed before I took a paid gig. I have a kids Christmas party in a few weeks so we'll find out soon if I have prepared enough.