Dear QIIMErs,
A few years ago, I wrote a short book, "Processing 16S data: an informal primer about 16S rRNA amplicon data". It's not a tutorial that shows you what buttons to push; it's an explanation for the reasons why all the little steps in amplicon data processing happen.
It's suitable for beginners, who don't know that much about 16S, and for folks who have used the data or read papers that use it, without understanding all the nuts and bolts.
You can download the pdf from github or browse the source files I used to compile it.
It could certainly use some updating, especially as de-noising and ASVs (100% OTUs) become more popular and the traditional 97% OTU becomes less popular.
I hope you find it helpful!