When I first got into online BtVS fandom, I started out in the Usenet newsgroups. From there I joined several mailing lists and forums, and eventaully LJ. I still check the Cold Dead Seed forum for updates on the Buffyverse actors, and I use the episode guides, transcripts, and screencaps on other sites for fic research and occasional iconning or manipping.

In my previous fandom, back in the age of the dinosaurs, I participated in local fan clubs, and in by-mail fan clubs, most of which involved making fanzines (at various times I wrote, illustrated, edited, and did layout and printing for half a dozen different zines.) One of the clubs I belonged to had several email mailing lists, and I eventually created a website for it.

I think it's easier to get into fandom via non-journaling sites, because you know that everyone there is there for the same reason you are. On journaling sites, it's a lot harder to connect with other fans unless you know someone who's already there.