Taking pictures of water droplets....?

Okay, i'm an amateur photographer. I have just recently acquired a Nikon D3000. I was stoked and couldn't wait to start taking pictures. I saw one type of picture that was really neat and i wanted to try it. So i did some research and got the stuff i needed to make the picture work. I set the aperture and the shutter speed (like it says to) and i put it on M (manual). I only have one problem. My pictures are coming out dark. So dark that you can't even make out what the picture is. I tried putting a light bulb as close as i can without getting it wet and it still doesn't work. Please Help