For some reason i am a beginner and did not want to go with D3100 or D5100 or D3200 those beginner models and decided to grab a second hand used D90 its kinda cheap now bcoz its old coz I'm thinking that maybe i can use it longer than those.
I came from a bridge camera so you can say i know nothing about lens or photography at the moment but is willing to learn. I'm thinking of buying body only and can you guys recommend me what sort of lens i should get? Will the kit lens be sufficient? I'm mainly going to do some portrait and landscapes is there a all in one lens? or is it best to buy 2 lens for separate reasons?
I did exactly what you did. Came from film to a bridge camera then to DSLR.
I too looked into each camera body and decided the D90 met my needs and wants for the money I could spend. Had I been able to afford it the D7100 was my first choice but, for half the cost of the D7100 body alone I got the D90 and three lenses.
My D90 came with the 18-55mm AF-S lens, 55-200mm VR lens and a 50mm f/1.8 "D" lens.
I ended up selling all of these lenses one at a time and collected another set of four lenses for my needs.
I now have the 18-70mm f/3.5 "D" lens, 28-105mm f/3.5 Macro "D" lens, the 70-300mm VR lens and, after foolishly selling my first one, again I have the 50mm f/1.8 "D".
For your stated needs I recommend at least two lenses. One for your landscapes and one for your portraits. Portraits really shine when using a prime lens such as the 50mm f/1.8 "D" or "G" model, "G" being the newer and sharper AF-S lens with silent wave motor, or the 35mm f/1.8 "G" lens.
For the D90, which is a crop sensor camera with built in focus motor (meaning you can use any AF lens Nikon ever made), there are many choices for any lens type.
Most of the newer "AF-S" lenses tend to be sharper and have slightly better image quality (IQ) than the older lenses. However, there are many of the older "D" lenses that will certainly give the newer lenses a tough run for their money if not actually outperform them in certain areas.
The newer AF-S lenses are usually faster to focus than the older but that is not that important in your case.
Now, back to your needed lenses.
The 18-55mm kit lens is a good lens for its price but it is far from the best lens. For landscapes you may want wider than 18mm due to the crop sensor of the D90 camera. The 18mm widest focal length, on a crop sensor camera, gives an actual field of view of a 27mm lens. To go really wide you have to get something in the range of 10mm-24mm, 11-16mm, 11-17mm or 16-24mm, etc. Still, 27mm is perfectly fine for landscape if you do not need extreme wide angle.
Other wide angle lenses to look at are the Nikkor 18-70mm f/3.5 "D" lens, as I have. It is tack sharp and build quality is better than the 18-55mm lens.
The 18-140mm AF-S lens is a great choice too and gives you some extra length that can be used as a portrait lens. It could be, in the words of a certain person, "The only lens you will ever need".
For portraits I really recommend a prime lens such as the 35mm or 50mm lenses. They just rock in terms of IQ and sharpness.
Good luck with your D90. You will love it as you come to know it.
Every photo I have posted on this forum has been taken with my D90. Browse my photo gallery if you have time and see what you think of some of the lenses I have used lately.
Mike D90's Images - Nikonites Gallery @ News