I'm back to my coverage of the presidential items on the National Recording Registry. Between 1975 and 1979, Reagan gave more than 1000 radio addresses, most of which he wrote himself. There is even an article I found that looks at the addresses where authorhship was unknown and they were able to prove that Reagan wrote most of them as well. The addresses covered a wide variety of topics and gave the nation insight into Reagan's beliefs before his presidential campaign in 1980.
These addresses have been released, in partial form, as Reagan in his Own Voice if you are interested in hearing many of them. I also was able to find two of them on YouTube on for you: Adoption and Sex Education. This article from the Wall Street Journal references one of his speeches on immigration as their look into Reagan's immigration beliefs.