So currently I own a Panasonic DMC-ZS7 which when I bought it was really good, and clearly I've not used it much because the reason I bought it was because I was told it takes good macro pictures(yea right). Anyways, I'm heavily trying to justify a reason to upgrade to a DSLR and I think the main thing stopping me is the price. That and I know absolutely nothing about taking pictures. So here's what I kind of figure that I want and all.

I want to stick with Nikon because from what I've read up on over the past few years most of their stuff stays interchangeable unlike Canon and Sony. So with that in mind I know cameras go out dated fast, so I want to be able to still get good stuff and not have to worry about changing the camera in general.

Now with that in mind I'm thinking of going with the D90 and I can either get the body only for a good price, or they sell one that comes with a lens but I have no idea if the lens is good or not.

Here is the macro lens that I'm set on going with:
TAMRON AF272NII700 90mm f/2.8 SP AF Di Macro Lens for Nikon AF

Now I want something for general pictures, say for a party or if I'm just out doors taking pictures of say nature? I know they have standard, telepathy and the telepathy zoom or whatever and that completely confuses me.

For like $200+ more I can get the one that comes with this lens:
AF-S DX NIKKOR 18-105mm f/3.5-5.6G ED VR Lens

Is that lens good, or would I do better off saving that $200+ and putting it with another $100-200 and get a better one?