Yes, I know that this an old topic but I have just found it.
I agree that it is usually perfectly possible search around and usually find a lot of useful information about all the services that are available. I am sorry, but to me that doesn't actually help much. There are a lot of instances where there is more than one way to achieve a desired result. As WhatsHisName wrote it will often come down to personal preference. Some ways might be better than others, some might be used in preference to another. Frequently the information you find does not say which OS it is relevant to. Rarely do you find out if it has superseded some other service that is no longer required. It is unusual to find out that this should, at least in the writers opinion, be used in preference to some other service (and why) and the thing I find most frustrating is that lot of the time information on the web is not dated so yuou have absolutely no idea how current it is.
I said useful. Yes, it is useful in an educational sense and perhaps that is what we should be aiming at. The caveat, the but, is if you want to do something now. Suppose you want to access another machine, try a new program or piece of hardware. It would be nice if there was somewhere you could go reasonably quickly to find out how to do it. Not to set out on a three month learning curve where you will end up so far away from the woods that there are no trees at all. I agree, that the long term goal is to learn what is going on ?under the hood?. The short term goal is to use it. And without, to paraphrase a long time advocate and devotee of Centos, breaking it and keeping the pieces.
By the way, I found this post while searching to find out if is the cups-config-daemon and cups-lpd should be running as well as cups. I have read up on both. I am none the wiser though..