LCD and Viewfinder
Nikon D300 has a Fixed Type 3" LCD screen with a resolution of 922k dots. Both the screen size and the screen resolution is up to the standards of this class.
D300 has a built-in Optical (pentaprism) viewfinder. The viewfinder has a coverage of 100% and a magnification ratio of 0.63x. 100% coverage ensures that what you see in the viewfinder while shooting matches exactly what you will get later in your image, helping accurate framing your shots and minimizes the need for cropping images later.
Max Shutter speed
Nikon D300 can shoot continuously at max speed of 6 fps
and has max shutter speed of 1/8000 sec
D300 has a built-in flash, and it also has a flash shoe to mount your external flashes too.
Nikon D300 features both Contrast Detection and Phase Detection autofocus (AF) systems which ensures speed and accuracy of focusing in most situations. The AF system has 51 points to choose from.
Unfortunately Nikon D300 doesn't have Video recording ability.
Connectivity and Storage
You can connect D300 to compatible devices via its HDMI port or USB 2.0 (480 Mbit/sec) port.
Nikon D300 is powered by battery which provides a shooting life of 1000 according to CIPA standards.
Considering that the average battery life of DSLR type cameras is 883 shots, its battery life is about average in its class but it would still be wise to invest in some spare batteries for long photo trips.
Battery Life Comparison in Semi-Pro DSLR Cameras
Nikon D850 with its 1840shots is the model with longest battery life among Semi-Pro DSLR cameras. Check the comparison of Nikon D300 vs Nikon D850 or take a look at Longest Battery Life DSLR cameras list.
Nikon D300 Features Compared to Main Competitors
You can download Nikon D300's User Manual here