The GAVO Data Center Helper Suite (DaCHS) is a publishing infrastructure for the Virtual Observatory, including a flexible component for ingesting and mapping data, integrated metadata handling with a publishing registry, and support for many VO protocols and standards.
You do not need to read all of the documentation to get started.
Of the installation guide, you probably only need the first couple of pages. At least skim over the tutorial before starting out, though, so you know what's discussed in there to return when you have a particular sort of data at hand.
Analogously, skim over the operations guide when you want to make your site public, and dig into the passages relevant to you as needed.
When you get error messages you don't understand, check the “Hints on common problems”. When you have some funky litte requirement the solution for which is not immediately obvious, try the “How do I” document. If what you want is not covered, ask the authors.
Always keep the reference under your pillow. Even the authors regularly go back there.
Almost all RDs for the services at the GAVO data center are available for your inspection, and the element reference may help you locate those relevant to whatever you're trying to do. There's nothing wrong with lavishly copying from there.
You can ignore the topic guides (booster grammars, preprocessing, anything else that might yet come) until you notice you need to read them.
To obtain the software (or parts of it), see http://soft.g-vo.org.
If you run a DaCHS server, please subscribe to the DaCHS-users mailing list. It is low volume (less than one mail a month), and you get to know when new releases come out. We'd also appreciate being able to alert our users in case a security hole should be discovered in the software (which hasn't happened so far, FWIW).
If you have questions regarding DaCHS, we'd appreciate if you subscribed and sent your question to the DaCHS-support list (if all support requests went on the list, we'd expect a volume of about one mail per day, but let's see). It has a public archive, and other users can profit from our (and your peers') answers, which is why we prefer the list to questions sent directly to firstname.lastname@example.org; these will of course still be answered.
Material related to DaCHS and the VO in general is also published now and then on GAVO's blog