Steve,
Here is my recommendation, browse my website in the following order:
1. http://www.digitalwavetheory.com/15_Planck_Units_and_Numerology.html
A bit of a background.
2. http://www.digitalwavetheory.com/29_Visualizing_Spin.html
This will give you a notion of how I visualize a graviton. Not quite the standard model.
3. http://www.digitalwavetheory.com/17_The_Case_for_Gravitons.html
Here is where it starts to get interesting. I make a wild guess that the graviton (even thought is not light) is ruled by the Planck-Einstein equation. Now we know the energy of each graviton. The graviton now looks like a Compton wavelength and it has a mass. From there I use good old Newton's law of gravitation force to get the number of gravitons connecting two masses. The mass of a graviton bundle is the mass of each graviton times the number of gravitons.
4. http://www.digitalwavetheory.com/19_Dark_Energy-Curved_SpaceTime.html
Here it is shown how extragalactic gravitons (as opposed to intergalactic gravitons) cause the accelerated expansion of the universe. The simple diagram is mindblowing!
5. http://www.digitalwavetheory.com/20_Dark_Energy_and_Mercurys_Orbit.html
This is the icing on the cake! I can calculate the mass of graviton bundle connecting Mercury to the Sun.
I make two assumptions:
a. The mass of the graviton bundle is distributed linearly along the length.
b. The mass of the graviton bundle has a center of mass that is halfway between Mercury and the Sun
Said another way: The graviton bundle connecting Mercury and the Sun looks like a planet halfway between Mercury and the Sun (Vulcan lives!).
I make a ratio to show how this (dark matter) planet causes mercury to precess. It is just relatively boring math to show that this precession agrees with measured values and Einstein's predicted values.
6. At this point go to: http://prespacetime.com/index.php/pst/article/view/1188/1163
This is a paper I wrote on this theory, and at the end it speculates how this theory is not that different than GR.
I think you will enjoy this, keep in mind that it is just a theory, and ask me questions.
Honestly, I think this is as close to explaining dark matter and dark energy as has been accomplished to date.
Run with it.
Don Limuti