Tonight I had the rare opportunity to read non-archiving stories (keeping a look out for archivable ones too, of course) and realised just how many ongoing fics there are on the community, and how difficult it can be to find the first/other chapters. Some authors kindly include links to previous chapters, and they're invaluable, but I realised that not everyone might know how, so I thought I'd offer a quick guide to inserting them.
In html setting:
<a href="THE LINK">Part One</a> / <a href="THE LINK">Part Two</a> / <a href="THE LINK">Part Three</a>
Which comes out looking like:
Part One / Part Two / Part Three
Couldn't be easier.
I don't use the Rich Text option, but it would seem that you just press the link button (a globe with a paper-clip or something beneath it) and add the URL. It doesn't come out looking quite so pretty but it still works.
Unlike a static site, journals and forums don't make it easy to catch up with ongoing works, and as a result authors miss out on a lot of readers. Inserting links is a great way to make sure you reach the maximum number of readers possible (this is especially true for the final chapter as many readers will wait for a story to be finished before they begin reading, and the search facilities on lj aren't great).
Anyway, I hope that helps.
ETA: For an added help to those who aren't that html inclined, Semagic is a Live Journal front end client that makes posting very easy, including adding links and all kinds of special gee gaws. It can be downloaded here: