franzferdipants is new to LiveJournal, and I offered to do him up a list of cool shit there is on here. So, without any ado, here is my list of
General
When writing entries, you can do a "Rich Text" update, or just use regular html tags. I don't bother with the former, html is where I'm at.
To do a cut-tag, like this thing, you use another command- < lj cut text = " What you want to display in the text " > and then you close it with < / lj-cut > Without the spaces, of course. Great for non-worksafe images, large entries, or triggery stuff people may not want to read.
To link to a community or user, the command is < lj user = " username " > or < lj comm = "communityname" >, again, sans spaces.
Communities
There are many cracktastic, fun-filled and educational communities on LiveJournal. Given that a lot of my interests are rather obscure, I'll stick with the really cracky ones, or the really popular ones...
ljsecret is just like PostSecret, only on LiveJournal. The idea is that people free themselves of the secrets which keep them alone and in emo silence and stuff, by doctoring images and adding text to admit the weight on their shoulders to the LJ community.
ohnotheydidnt is a celebrity trash community. It's fun. It's full of ridiculous, stupid and just plain wrong things going on in the celebrity world, as well as lashings of harsh criticism and bitchiness from watchers.
metaquotes: Funny things, and the context they were said in on LJ, collected by readers for other people to giggle at. :)
customers_suck: a community for hilarious, horrible, gross and WRONG horror stories about how much customers can and do, in fact, suck.
bad_rpers_suck is devoted to people bitching about bad roleplayers. I love this one: it's a good one to check out for basic ettiquette, as well as some hilariously WRONG descriptions, stories, MarySues and more.
stupidpetowners is pretty busy, and it's half horror stories that make you want to kill people, half clueless people who shouldn't be allowed to look after houseplants let alone living critters, and the odd insanely wanky and often classist post. ("OMG! You animal abuser! You feed your dog non-organic el cheapo dog food!") It has a sister community which aims to stop people becoming stupid pet owners: spo_prevention.
urban_decay is photographs of, well, urban decay. Graffiti, abandoned buildings... you'll find it all here. I lurk when I have time and I love it.
melbournemaniac, I'm not a member of, but just about everyone else in Melbourne is. It's sort of like a social square/gig guide for Melbourne. (Given that I don't get out much, it doesn't really have much use for me, but apparently it's good shit and leadgend mentioned it, and he seems to know everyone, so it's sorta where it's at.)
overheardinmelb: based on a similar-styled thing, Melbournians document weird, stupid, hilarious or just interesting things they've overheard from others in Melbourne. A lot of these things are very very funny, though some are stupid enough to make you want to go "I'm surrounded by eeeeeediots." (As are some of the comments.)
current_affairs is politislash from all over the world. Yay politislash.
gaybours is a slash community all about Aussie's beloved Neighbours. Paul and Dylan are SO fucking, okay? *points to icon*
slacken_ties is a Franz Ferdinand slash community, which the band apparently know about and support. How cool is that?
mac_hearts_pc is a slash community about the Mac/PC ads by Apple, urging people to buy their wares with the two systems being represented by two men who seem to have a lot going for them in the way of subtext. This is probably my favourite publically-accessible piece of fanfiction in any fandom.
Also, doing a search and pulling down the bar to "Interests" will list communities and users interested in the same thing you listed, which can make for some nifty discoveries. It's so cool finding people with that same obscure interest you have sometimes!
Have fun!
EDIT: Friendslist, are there any LJ tricks or places I've failed to mention? Let us hear 'em in the comments!