Suggest lens to have for Nikon D5000 in children and family photography?

I would like some suggestions before I go and buy the wrong lenses for what I want to obtain.
I would like sharp crisp eyes and close ups of people, children.
Please give your suggestions and why you found them to be good for you.

I appreciate it, before I spend money on some thing I may not be happy with.

Having a good lens is a necessary condition for sharp, crisp eyes on the photos, but not a sufficient one. It also takes some skill.

Anyway, the 50mm/1.8D would have been a very good choice if you had a D90, but it won't autofocus on your D5000. As a portrait lens for the D5000 you'd have to get the 50mm/1.4G (not D!), which is much more expensive. Or the Micro Nikkor 60mm/2.8.It's very good for portraits unless you want particularly shallow depth of field. It's less low light capable than the 50/1.4, but it's a macro lens, so you get that capability instead. For partial portraits, such as eye close ups, it would be a premier choice.

Really depends what you are trying to achieve or what your skills are like…

35mm f/1.8 or 50mm f/1.4 lens…

or any other lens will do, if your skills are sufficient enough…

18-105 if this is your first DLR. Decent performer and the range is very convenient for dealing with people, one lens to go from posed group shots in reasonably close situations to candid portraits at more of a distance.

Your kit lens should be fine for portraits. You won't need to get another. Just make sure you fill the frame. Spend your money on portable studio lighting instead. It will cost less and you will expand your capabilities immensely.