This site explains that the there are regions of CMB that are slightly denser than others and the causes and effects of this. The regions cause temperature changes, which cause the ripples in space, which ultimately develop into the stars and galaxies we observe today. This site also discusses the complications with such scenarios. It shows that if the Universe is open, the angular scales for microwave shifts will be smaller. Another graph in this site shows that the behavior of the early universe fluid depended upon the relative number densities of electrons and photons.
Additional graphs represent redshifts due to photon energy density.
This site contains a little information on COBE, the first satellite to show evidence for CMB fluctuations. It also gives detailed information on how the photons redshifted to form microwaves into what was once visible light. Future experiments on learning more about the microwave horizon and establishing whether a first generation of stars or galaxies reionized all intergalactic hydrogen are explained in this article. This site states that patches of the highest temperature correspond to the longest sound wave that existed when the universe was 300,000 years old. This article also briefly describes on the universe cooled so that photons travel freely in space.