Best book to get (and a steal at $5) is The Leopard Gecko Manual. It has all the info you need on care, feeding, morphs, and what to look for in signs of sickness. Really, even us "old timers" wouldn't do without it.
Best substrate is papertowels. Some do tiles, but it is harder to heat them and you have to get lead free tiles, which I've found isn't as easy as it sounds if you want something that looks nice. (ie, not red clay) The problem with anything else, namely sand, is the gecko may/will eat some and it can cause impaction and that is vet time. Some people feel comfortable moving to sand once the gecko is an adult, but there is still a chance of impaction. We'd never take that chance, we keep everyone on papertowels their whole lives. The nice towel like all white ones look fine to me. Another advantage is you only need to remove the "bathroom" corner's towel weekly, the rest can be changed monthly.
You only need to keep the humidity up in a small enclosure, a humid hide. These are easily made from plastic food containers, cut a hole or two into the sides for entrances/exit line with paper towels (again) and then moisten those towels as needed and set the hide over the warm end. Shed problems with a moist hide are rare, and only really a huge worry if constricting the toes. We have tons of "tricks" to take care, it is much less of a problem than in snakes, at least from what my friends complain about their boas.
I've had both male and females, there isn't much difference in temperament or handling, on average males should get bigger... but then we recently grew an almost 10" female, so care comes into play too.
You should be able to find a ton of normals, but we are just entering into breeding time. The genetics will almost always produce some normals and you can get them at a great discount. Our independent herp store sells their extra normals for $19.
If you are looking for a brown gecko, tremper chocolates are easy to come by and, in my opinion, pretty cute to boot. (see below)
Please ask as many questions as you like, we love to answer everything BEFORE the gecko is brought home. I still highly suggest the book, it is straight forward and, depending on the age of the child, might even be within her reading comprehension, but really, the book is the finest reference for all of us.
Welcome and ask away!
Here is our current albino:

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0.1 Albino Leo Gecko
0.1 Crested Gecko
1.0 Dear Boyfriend
Departed: Harvey and Spock