This site sheds light on some of the core concepts in Buddhism.

The link leads to the page description on emptiness as form/It has a pretty thorough and easy to understand explanation on one of the harder/trickier concepts. It incorporates physics and math to demonstrate a more practical application.

Here is an excerpt on karma and rebirth.

If the idea of non-self sounds odd, then it must sound even more curious that non-self can be reborn. There is a seeming contradiction between the canon of rebirth and that of the non-self, which even many Buddhists find difficult to understand. The contradiction is, however, only on the surface and can be solved if one pictures the self as the result of karmic formation. This can be put into less abstract words:
If we imagine the world as an ocean, we are like the ripples on the ocean. Formations like ripples and waves occur, because of wind, tides, and other kinetic forces. In the Buddhist analogy, the universe is in motion due to karmic forces. A ripple, a wave, or a billow may seem as an individual entity for a moment, creating the illusion that it has a self, but it is gone in the next moment. The truth is that all individuals are one. A ripple is a temporary phenomenon; it is just water in motion. We know that kinetic energy causes wave forms on a body of water and it would be ridiculous to say that a single ripple or wave has a self.
Similarly, in case of beings, the process of coming into life and being conditioned in a particular way is caused by karmic forces. The up and down of the ocean's waves corresponds with the rotation of the wheel of life. The sea that surges, falls, and resurges, is the life that is born, dies, and is reborn again. It is therefore obvious that we should not focus on the temporary phenomenon of the wave, but on the force that causes, forms, and drives it. Nothing else is said, although in more practical terms, in the Eightfold Path.