These projects seem to do a very poor job of presenting themselves. I spent a good deal of time reading about each and have yet to have a really good grasp of what they are for. They seem to be about maintaining a cluster of hardware servers to run arbitrary services with configuration and fail over.
Do you know of some decent article, blog post, video, whatever that presents these products, what they are good for and a typical use case?
I agree wholeheartedly about the failure to communicate clearly. At least one contributing factor to the present situation is the lucrative consulting that exists around these solution types and helps to fund their development. Simply put, if it was that easy, everyone would be doing it (and we'd be out of a job). However, to be fair, things change fast and there does exist a lot of good documentation - just not necessarily perfectly up to date for your scenario. Your assumption is perfectly correct. Have a look at http://www.linbit.com/en/downloads/tech-guides or http://clusterlabs.org/doc/ or try #linux-ha or #linux-cluster on freenode.
Do you know of some decent article, blog post, video, whatever that presents these products, what they are good for and a typical use case?