Clara -
18-50 - gives you a little macro and portrait - snapshot capability. **I use this one most**
55-200 - (Mine is 75-300) I use this for mostly outdoor events like sports where I need to get close and want tight cropped action shots but physically I cannot be on the field with my small lens
For getting close to animals etc...without being noticed
(...or eaten *LOL*) Other then that - it is not really good for snapshot type photos. Also if it's not an image stabilize lens you have to consider camera shake as well.
I would just consider what type of photos you like and go with that lens
If you have a best buy near you or any place that sells cameras go in and check out how the way the lenses zoom. Get a feel for them first
I always find an on-hand trial never fails me
Congrats on finally getting the money!! I am glad they finally came through! Have fun picking the lens out!! Can't wait to see what you decide! So exciting!