Hi, I came to the Beginners' forum but after some browsing it sure doesn't look like u guys are beginners here 'coz ur photos are great and the camera bodies and lenses u guys have seem rather pro. I'm really really a beginner, or a newb if u wish, or maybe even called a hobbyist. I own a nikon d80 and have the default lenses 18-135 and bought a 50mm f/1.8d. I'm looking to buy either a versatile lens for portrait and/or food, or basically just another lens for scenery. Okay maybe I should just continue lurking ard photography forums instead of asking very open-ended questions?
I don't know much about Nikon lenses (I'm a Canon shooter) but do you already have some lighting? Like off-camera speedlites or strobes? You're going to need them for portraits and product photography. Strobist: Lighting 101 Strobist: Lighting 102
A rule of thumb for portrait photography is to use a lens with a focal length twice the length of the diagonal of the CCD or film frame. This diagonal on a D80 is 28.4mm. Twice that is 56.8mm so your 50mm lens should be good for for portraits. Your zoom lens should do fine for scenery.