The contents of a zipped (compressed) for Poser should contain the same folder hierarchy as you would find in the Poser runtime folder.  I would recommend decompressing your content into a temporary folder, open it's browser window and also open the Poser runtime folder in a separate browser window.  Compare the folders.  Do you see simularities?  If the answer is yes, then you can proceed down the hierarchy tree and note where other folders are located and how they are arranged. 

Once you understand the fundamental folder structure Poser uses to organize and detect content, your next step is to drag those folders into their appropriate folders.  I would recommend using the Download folder, it doesn't have content and you can easily keep track of the content. 

But you must understand, runtime folders can and will grow very quickly, and you can lose track of your content.  That is the reason many seasoned users create multiple external runtime folders to organize content from the start.  Again, it is important that you understand completely how compressed content is package and where they go into a runtime folder.  Some are easily managed, others may have folders completely nested in wrong places; you must learn to see the difference and correct it when transporting them to Poser.  Or else, you may never find them in the main Library.

Unfortunately, I am not currently at my Poser Computer where I can illustrate some steps, but, as suggested at another thread, you should do some research on your own before posting specific help.  We can only hand hold to a certain extent, the rest is up to you.  And please refer to the manual, it does contain fundamental information to get you started.