What to do? How to get sharp crisp pics?

I'm a beginner with a strong passion in photography and I need some support and knowledge to improve. I have a Nikon D5000 and a 55-200mm lens. I want to take people pics that are sharp and crisp. How do I gain this? A different lens or should I change to Canon? If so which model and lens to go with.
Please check out my photos on Facebook at Myhunnahbee Photography. Any feed back would be appreciated to improve. We only learn by trial and time and much needed feedback.

Let's start with the reasons why an image might come out blurry:

1. Slow shutter speed could cause camera shake, which would produce a blurry image
2. Poor focus acquisition would result in a soft image
3. Your subject could be moving and causing a motion blur
4. Your ISO could be set to a very high number, resulting in lots of noise and loss of detail

If you have an "Auto-ISO" feature in your camera, set it to "On"
Shoot in Aperture-Priority mode and set aperture to the lowest value when I shoot in low light.
If you have Image Stabilizer (VR on Nikon) on your lens make sure its "On"
There's a lot more solution to fix this kind of problems but first you need to know where the problem exactly is.

Quality of image and sharpness is bases upon four things. Lens (glass) quality. Shutter speed stopping the action of your subject, VR type lenses which by computer stop or minimize camera shake, and flash. If you can't shoot in bright light and can use high shutter speeds, use flash even outdoors. If you can get or have a VR lens make sure it is operating correctly. Keep in mind that most images shot with digital cameras require after image corrections within say Photoshop or some other program to improve sharpening. But the better the initial image the better the end result will be. Also make sure you are using a large 16gb or 32gb card so you can have the camera set to it's highest and largest quality image. What kind of camera means nothing they are that close in quality. Making sure you are using the best lens you can afford is paramount. Also when you can upgrading to the best quality Nikon you can afford comes later.

Repeat this 100 times: "It isn't the camera its the photographer."

It wouldn't matter if you bought a Canon or Sony or Pentax or Olympus or even a Hasselblad.

Now find a comfy chair in an area with good lighting and settle in to READ & STUDY the Owner's Manual for your fine camera. This is how you actually learn to use it.

These sites will also help you:

http://www.photonhead.com
http://www.kamerasimulator.se/eng/?page_id=2
http://www.digital-photography-school.com
http://www.illustratedphotography.com/photography-tips/basic

If you are trying to shoot indoors without the flash you need to look at this site to gain understanding of the difficulties involved.

http://www.calculator.org/...osure.aspx Look at the Scene 'Domestic interiors at night, subject lit by campfire or bonfire', use ISO 400 and then look at the table of f-stop/shutter speed combinations.
Those shutter speeds sure get slow don't they? Any subject movement will be recorded as an unrecognizable blur at any shutter speed below 1/125 sec.

Photography is an on-going, never ending learning experience.

Use flash to make clean sharp images, thats what i do

edit: and thats what the professionals do… Using lights and off camera flash is what separates the good from the rest, - i see someone doesn't agree - have a look at their photos for proof… Dot dot