I own a Nikon D3000 and need some advice?

What are some other great lenses for the Nikon D3000? I shoot portraits and weddings so I'm looking for a lens good for that. And as far as flash attachments? Get one? Not get one?

What lenses do you already have?

A 50mm/1.8G lens which will work like a charm for portraits and low light has just been released. Or, if you can afford to spend a bit more, get the 50mm/1.4G. There are also "D" versions of these around, but those won't autofocus on your camera.

A flash is extremely helpful for portraits, but it'll be necessary to know your "shooting style". Are you willing to spend some time to set up off camera flashes with manual output, or do you want to keep your flash on the camera, bounce it and use TTL? There's a lot to be said about this, so that's pretty much a topic for its own question.