This is one of the coolest places in Vegas to go wether you have children or not! I took my younger brother and his friends here for his 19th birthday and on another occasion with Jason, and everyone has always had a really good time.
We always start off at the petting zoo, and I suggest you bring a pocket full of quarters to feed the animals. You can get them from the restaurant, but it seems like they get really annoyed and it's a bit of a wait to get change. Bring a camera, you'll want to capture these memories. You might also want to consider having baby wipes on hand as the hand washing station can be fussy.
Next we take a trip through the town; this is another place to capture some really adorable photos. They also have a show in front of the "Town Hall" every couple hours, which they will tell you the schedule for when you purchase your tickets.
Finish off heading over to the gift shop, where we picked up a raccoon hat (because no young man can turn 19 without one!). He wore it cosmic bowling that night, and all the young ladies were.. how you say "all over his nuts". I thought it was amusing that the simplest of things can get so much attention.
Worth the small price tag. I'll definitely be back.