Add a new page:
This is an old revision of the document!
The best introductions are Relativity, Gravitation and Cosmology by Ta-Pei Cheng and The Early Universe by Edward Kolb and Michael S. Turner
Many questions that frequently pop up are answered here
https://preposterousuniverse.com/cosmologyprimer/faq.html
and here
http://astro.utoronto.ca/~cczhu/ZhuQual.pdf
Another nice introduction to the CMB and related effects is A Poor Man’s CMB Primer