Usually, when you connect a device such as a camera to the computer, it will appear in My Computer. If you head off to My Computer, the name of your camera may be listed next to a Camera icon or there might be a new drive that wasn't there before which is the memory card inside the camera. Double click on the correct icon.
Sometimes the images may be a few folders deep, but if you look, they are there. You can then simply right click on the images you want, copy them to a folder on your computer e.g. My Pictures and then attach them to your email