For Writers of Original Fiction

I have no firsthand experience; I'm to-be-published, in that I know my story's been accepted, but the process as such hasn't really started for me yet. As far as I know, though, self-publishing is easier in the sense that you can just DO it, without having to fight to be accepted by an agent or a publisher. Unfortunately, that makes it harder in a different way; self-published books tend to be fairly low-quality (not all, but many) since there's no acceptance progress, you can publish whatever you like. This also means that self-publishing has a bit of a bad reputation (much like fanfiction: much of it is bad, some of it is excellent, and some is in-between, but the amount of bad is greater than the amount of good, so the whole field tends to be tarred with the same negative brush). And most self-published books don't do well because they aren't promoted, distributed in bookshops, etc. If you go the traditional route, the publisher will take of all of that and they have the network, contacts, etc, which are necessary to do it.

So... I would try the traditional way first, if you can handle the idea of getting rejected many times before being accepted (if ever). If you want to self-publish, and do well with it, you'll have to do quite a lot of work promoting and selling the book. This is why I know it's not for me, personally: I'm a really bad salesperson and I can't advertise worth a damn. But that may well be different for you.