Is there a plugin or an easy (semi-automated) way of adding "Next" and "Previous" links to a Redmine wiki page that is part of a sequence of pages (in my case, it's for a sequential tutorial)?
I guess the core problem here is that wiki's are not generally designed for making multi-page tutorials or am I missing something?
AFAIK there is no automagic way of doing this, there are to ways you could implement it,
Link directly
You could always link to a wiki page directly by it's name, like
[[Page_1]]
or decorate the page link with a description;
[[Page_1|< < Previous]]
Will show as < < Previous
Use Parent-Child relationships
On a newly created page, goto Rename and choose a parent Wiki page. That willl display a breadcrumb bar allowing backwards navigation. The page(s) will also show as child page(s) if you want to list all Wiki pages on Index By Title.