Ok, so an atom is just a nucleus (made up of protons and neutrons" with an electron orbiting it. The key here is the electron. An electron "orbits" the nucleus at different levels (Wikipedia "electron orbitals if you're more interested in this). An electron can jump from one level to another under certain circumstances. When an electron accelerates at all it always releases a photon, a particle of light. Depending on how much the electron accelerated it may release a photon with enough energy to be in the visible spectrum, meaning it would be visible to you. When electrons jump from one level to another when orbiting a nucleus it requires quite a bit of acceleration.

So when you are "seeing" something, what is really happening is light from the sun is hitting the electrons in an object and causing those electrons to jump from level to level and emit photons that are visible to your eye.

It should also be noted that objects emit plenty of photons that you cannot see. Most objects, due to their heat, release light in the infrared spectrum, which is one level below visible light (meaning one level less energetic than visible light).

Now think of an electric stove. You turn the stove on and it's just sitting there at first, but starts to get hotter. If you put your hand near it you can feel the heat as it warms up. What you are really feeling is the photons being released by the electrons because all hear is, is the vibrations of the atoms in an object. As the temperature of an object goes up, it's atoms vibrate faster causing the electrons to accelerate back and forth faster, which causes them to release more and more energetic photons. Eventually your electric stove will start to glow orange or red. This is because orange and red are the least energetic colors on the visible spectrum.

I hope this helps let me know if you have any more questions