There isn't any good user help because the plugin is *dead*. Heck, even I don't use it anymore. All the bits of it I've either stopping using or replaced with other bits.
Publish - I use Jetpack's Publicize for this now. It's a ton easier to set up and use and it generally works swell.
Login and Registration - I just stopped using them. Frankly, I don't like Facebook's authentication mechanisms much, and the integration wasn't very good to begin with.
Photos - I don't use FB Photos anymore, because FB's Photo management is frankly a travesty. There's a dozen better services out there, and there's great plugins for them available.
All the various widgets - Each one of them can be replicated by simply visiting https://developers.facebook.com/docs/plugins/ , selecting whatever widget you like, filling in the details, and copy/pasting the code they give you into a WordPress Text Widget. Works just fine.
Like Button - There's at least 30 plugins in the directory to do like buttons just as effectively as SFC was. If you want to bother, I found that simply having the button on the page slowed the page load time down massively, and in the end, it wasn't worth it. Publishing the post to Facebook was more effective than having that useless button there. But many other sharing plugins exist too if you like that sort of thing.
Comment pullback - Was not very effective, and did not assist in communication. In short, comments on Facebook are generally pretty terrible and of little to no value. Not the sort of thing I'd want displayed on my site. And, FB comemnts are difficult to moderate, so there's no way to keep them cleaned up easily.
Comment using FB - Jetpack has a nifty Comment box thing that works great for FB/Twitter/G+ logins. Use that if you want it. It's like 100 times better than SFC was in this respect.
OpenGraph - Good idea, failed execution. In the long run, OpenGraph is kind of weak compared to something more powerful like schema.org. And schema.org can be built into the theme itself quite effectively and simply, if you're careful about it. Plus, schema.org gets you Google benefits and clever things there, so much nicer all around. Doesn't hurt to have OpenGraph, but doesn't help much either.
And so forth. Basically, everything "Facebook" turned out to not be worth the effort I spent in developing the code to talk to it. The few bits that did help were done better by other people, more effectively. It no longer makes any sense for anybody to use SFC at all, for anything. Switch to a better plugin. Heck, use Jetpack. It's all you really need there. But if you do want deep integration, use the official Facebook plugin. It has most of the same code SFC had, but updated and better written.