As others have said on this thread, the D300 is an excellent camera - a joy to use. A good place to learn about the camera for free is at http://www.kenrockwell.com/nikon/d300.htm ; not just a review, but a wealth of info. He takes you thru all of the camera's setting/menus/buttons, etc., and advises you on how and why he sets up the D300 to attain the in-camera color you want. He gives a good run-thru on things like Picture Controls, White Balance, Active D-Lighting, the D300's AF settings, and the basics on personalizing the camera.
You may have to take him with a pinch of salt - so to speak - as he does have his own style of review. But give him a read, and if you like his style, then you'll appreciate the info he dispenses. At least you'll come out of it with a full handle on how to set up and use your D300 - all for free.
One of the things we as photo enthusiasts neglect to do most often is to use our tools to the fullest of their abilities, only to then rush out and buy the latest models. The more we understand the tool the more we are apt to wring the neck of the darn thing to get all the juice out of it - so to speak. Rockwell does have a lot to say, and it's free. And it's a good place to start.