https://www.rfc-editor.org/rfc-index.html
in contrast to this, a brief and lively history is the book Where Wizards Stay Up Late by Katie Hafner and Matthew Lyon.
Here is a good site to see what obsoletes and is superseded by what. https://www.potaroo.net/ietf/html/rfcindex.html
Implementing something like DNS, however, requires jumping between multiple documents and understanding what's deprecated and extended by each.
However, I just saw that rfc-editor.org actually lists these links between them, e.g. https://www.rfc-editor.org/info/rfc2822 has links to both 822 and to 5322.