There are lots of people that both know what they are talking about, and who will help with any question, stupid or not.  It gives us something to do and helps with the feelings of superiority ;)

With the library panel in windows, a single left click in windows opens the selected library, a single left click at the top will close it and bring back the libraries list.   click on any library folder to open it, click on the arrow thing at the top to return one level. 

The manual is available off the help menu item , or navigate to the Poser 7 program folder and look for the pdf file.

I dont know about macs so cant help.
 
Develop a thick skin, ignore stuff thats not helpful. Any question you dont know the answer to is worth asking but RTFM (read the furnished manual) is wise.   Bear in mind that renderosity is a community of people and like any community has all sorts. ;)