http://www.nikonchat.com/3500-coolpix/
How do I turn off the flash on a Nikon CoolPix 3500?
This is a digital camera that I was given a few years ago for work, but I use it for everything. There are times when I would like to not have even a delayed flash, but I’ve lost the manual and don’t know how to change it.
Look on the back. I think most Coolpix cameras are pretty much similar, and I used to have one. There should be a round button with different symbols on it. The one that looks like a lightning bolt means flash. Push it and you should get options for flash. The international sign for “no” should be one of your options. Pushing that will turn off the flash.
Okay, I looked at the manual PDF download (Guide to Digital Photography–the first link), and page 43 tells all about your flash. You have a flash button on the back of your camera. Push it for your flash modes. Off will be the lightning bolt in a circle with a slash.
Genom en Nikon Coolpix 3500
Nikon News