1. An infinitely dense atom of matter explodes, releasing all matter in the known universe.
2. This matter clumps together forming rocks and dust; that which doesnt compact remains as gas.
3. The rocks and dust are pulled in to each other by their own gravity. These clumps get bigger and bigger, and form planets.
4. Gas and dust clouds, better known as nebulae, (sing. nebula) begin to react, clump together and generate heat. Stars are formed out of these nebulae (unsure of the process).
5. The stars, with their powerful gravitational pulls, drag in planets to form solar systems. This happens on a larger scale as well, as groups of millions of stars are formed into galaxies, huge swirling discs containing millions of stars each.
That's where we are today.