I know this is all beginner stuff, but I cannot seem to find a comprehensive tutorial online.

 I just purchased Morphs++ for Daz3d and I have absolutely no idea how to use it. It was hard enough to find the morphs in the content directory, but now when I load in a V4 and try to load the morphs I get this message:

"To avoid seeing this message make sure that the poser content directories are set up correctly"

Clearly, on my computer, they're not, but I don't know how they're supposed to be set up. Clarification, anyone?

make sure you have them installed into the same content folder that your v4 is and make sure you run your v4 updater link that installing her puts on your desktop when you install her after you install the morphs and initialize them.  if you still get that mseesage then it's something beyond me

I'd guess this one of the groups or channels pz2 files, given your other post on Morphs++ - it's a good diea to tell us which file DS reports as missing as the error you quote is a fairly generic "I can't find something" on its own.

 It's weird. After much frustration and advice from others on this board, I got the morphs to load last night and mostly everything else that I purchased (a character morph, a pureskin for V4, some clothes, some hair), but I still keep getting that message every time I try to load in an eye or some sort or reflection -- usually things that are jpegs. With the Pureskin, for example, it came as two separate downloads, each with its own runtime and textures folders (there's only one library among the two). I assumed the file was just too big to put it all in one download, so I saved both runtimes in two side-by-side folders marked "Pureskin 01 and 02" or something like that, since I didn't know if I was supposed to put them together. Now in Daz,  I can load the body mats easy, but when I try to load one of the eyes or eye reflection treatments -- all of which, I believe, are in the 02 folder without the library -- I get that "can't find" message. If I choose to "locate" them from the drop-down menu, I can find it fairly easy, click on it, and load it in. So it feels like, once again, there's a problem with how my content is mapped. I really don't find the Daz content directory system in any way intuitive or practical and it's given me so much trouble just in the span of a few days.

Yes, the things are designed to merge - unless you want to split content you should unpack all parts to the same folder so that the Runtimes are meged together (and with any other content already installed) and that Runtime should be in a folder you have selected as a Poser content directory (not in a sub-folder).

Poser files contain relative paths - Runtime and any sub-folders. What you are doing when you set up content directories is giving DS a list of places to look for the Runtime folder.

 Okay, thanks. So how do I set up a folder as a proper Poser content directory? 

I must be doing in wrong because when I go to "Directories" and, then, "Search for Content," it never gives me any options to narrow the search and therefore it searches my entire hard drive, taking forever.

In Edit>Preferences>Directories, after switching to the list of Poser directories using the long buton at the top, click Add and seelct the folder that holds the Runtime folder you want.