Instead of placing the link to the recommended resource i.e. the second
edition in second place, push it up to the top of the list. In fact,
push the link to the first edition always at the bottom.
To emphasise even more that's where new visitors should go, bolden the
first link, and make the first-ed link smaller.
All this as well as a slight edit and simplification of the copy is
designed to make the new and recommended resources the primary path
readers take, without hiding the old resource completely.
To improve immediate value and reduce discard-because-not-useful factor
upon arriving at a page which does not contain the content you were
expecting, add a small blurb taken/adapted from the newer source,
optionally accompanied by a code sample describing the feature.
However, due to the transitive nature of this resource, there must be no
content here that isn't available elsewhere.
To make it clearer where links are going, eliminate entirely the
language of "Related" or the long verbose book titles. Instead, simply
prefix with "In the first/second edition" as needed, and in similar
style for other resources like the reference or the Unsafe book.
Add the target's title, i.e. chapter number, name, and sometimes
subsection, directly to the link copy.
Unless it is the correct place to go, never link to the index of the
second edition as fallback. Point instead to different books, to the
reference, to the API documentation, etc.
And reword the blurb to include what was previously in the title.
This makes it easier to see that one has arrived to the right place:
beforehand, the only indication was through the link target for the
first edition; it was nowhere in the copy itself for most pages.