I would guess that majority of the cameras today are bought by parents to take pictures of their kids. They want to capture all the memories of them growing up, but photographing children is not for the faint of heart.
Creating professional looking pictures is less a question of expensive equipment, but more of experience. Depending on their age or personality, kids can love or hate when they are photographed. To catch good pictures, you need to be patient and let them time to get used to your presence. Besides all these, they move around with the speed of light, which does not make things easier.
The two major things you need to decide on is the environment and the light. I prefer playgrounds or parks, right after the sunrise. This is ideal, because will give a very nice warm feeling to the picture and children are in their best form in the morning when they are not tired. Just let them play around and forget about you and do not force them to pose to the camera.
The other big advantage of this time of the day is that you do not need to use a flash. Flash can give a creative look to your photos, but it is significantly more difficult to use correctly. What you also have to keep in mind is, that children will rarely wait for you to set it up. By the time you are done, they will be gone.
So what are then the major things you need to be aware of to create great photos of your kids and not get frustrated:
be patient and build a relationship with them
photograph them in places they are familiar with and where they feel comfortable
keep it simple technically - use natural light with a reflector if needed, but forget the flash if not absolutely necessary
let them be kids and don't force them in any posing that you might think looks nice, but they hate it
...and most of all, enjoy the process!!!!!