Yesterday i received my nikon d3200 as my first entry into DSLR ownership.
Today i went to a local nature park to have a play with some different settings.
At present i only have the standard 18 - 55mm lens and dont have a tripod so i learnt today you cant have long exposures when going handheld.
You may not be aware but there is a general rule of thumb for choosing a good shutter speed that should give you a sharp photo for any given focal length.
Basically, the longer the focal length of the lens the faster the shutter must be. Longer the focal length the narrower the field of view, and therefore the few degrees error of rotation you make when shaking will result in larger and larger movements of the image across the sensor.
In the 35mm Film days people used the ratio of 1/focal length as a starting point. E.g., with a 200mm lens 1/200 would give you sharp photos most of the time. However, for crops cameras the effective focal length is longer because the field of view is narrower, therefore you have to take into account the crop factor. so with a Nikon crop camera, a 200mm lens would need 1/(200*1.5) so about 1/300th of a second.
Remember, this is only a ballpark figure, if you have shaky hands then you will need faster, but if you are a professional sniper in the army then a much slower shutter speed will suffice. In general of course better to be cautious and get a shutter speed well above what you need.
Also the rule of thumb assume something like 95% of the time the photo will be sharp, I tend to prefer to get like 99.9% of the photos free form camera shake induced blur so always push higher (or take multiple exposures to improve my odds).
The VR/IS in modern lenses goes someway to reduce this, in general it is safe to subtract about 2 stops (so a factor of 4). Some lenses do better, some worse, and it all comes down to a statistical game. If i get a 90% keeper rate with a 200mm lens using 1/300th of a second then switching on VR will hopefully give me almost a 100%., if my shutter speed drops to 1/100ths second then i should still be OK with VR most of the time but can expect a few failures.
You also have to consider the subject motion. It may be you can hold you lens really steady but if the subject is a running animal/person/ or moving vehicle then you will need to maintain a sufficiently fast shutter speed. 1/500th second is a starting value for faster movements. Something like 1/100th is good for people standing with gentle movement etc.
Importantly, VR wont help here, if you are photographing a flying bird then you will want your shutter speed high enough to ensure no motion blur.
