Best lens (es) for Nikon D90 DSLR?

I just purchased a used D90 DSLR, but I'm confused as to what kind of lens I should buy that goes with it. I'm just a beginner and I've been exeprimenting with point-and-shoot cameras for the past 2 yrs and this is a significant leap from there. I'm looking for something not that expensive and I mostly shoot portraits and landscapes.

Any good suggestions people?

I believe youre looking for a Nikkor VRII lens with an 18-200 range, it'll suit your need from close up to wide angle uses unless you're a serious or professional photographer who must change lens from time to time, i got mine more than a year ago & it still amazes me & my friends till now with just 1 lens that can cover my amateur needs.

Why not buy a kit lens? The 18-55 is dirt cheap, the 18-105 is a bit more expensive but really versatile. I always advice newbies these two because they're an excellent way to discover what you really want out of a lens.

I would consider Opteka 650-2600mm High Definition Telephoto Zoom Lens for Nikon D3, D3S, D3X, D40, D40x, D50, D60, D70, D80, D90, D100, D200, D300, D300S, D700, D3000, D3100, D5000, & D7000 Digital SLR Cameras

Opteka 650-1300mm f/8-16 Telephoto Zoom Lens with 2X Teleconverter (650-2600mm)
High-index / low-dispersion optical glass, Fully multi-coated, every element, Anti-reflection coating
Designed to maximize day and night shots by providing maximum light and image transmission
Great for the wildlife or nature photographer who wants to be hidden while taking photos of the subject
Carring bag and lens caps included