Some of the most important concepts in cosmology
are well explained in Nick Strobel's notes, and I suggest you start by
reviewing his pages on

- Other Galaxies,
especially on the Hubble
Law.
- Cosmology: Observations and Some
Implications. Pay particular attention to the
key concepts of homogeneity and isotropy.
- Cosmology: Dark matter.
- Cosmology: Embellishments on the Big Bang.

Be warned that Strobel's section on the Fate of
the Universe is seriously out of date. Many of the statements there are wrong
because they incorrectly take for granted that the cosmological constant is
zero.

We now need to look at these ideas in a bit more
mathematical detail.

- 1.1
Cosmological expansion and redshift
- 1.2
The Geometry of the Universe
- 1.3
Dynamics of the Universe
- 1.4
Observational cosmology