Do you have DAZ Studio as well as Poser or just Poser and some DAZ content (the figures and so on)? If you don't have the DAZ Studio application you should be asking in the Poser forum.

With DAZ content, you run the installers (if you are using Poser only you can skip any files that have names ending DS) and point them, by default, to the folder you installed Poser in (so that would most likely be something like C:Program FileseFrontierPoser 7 on Windows - though under Vista and Windows 7 installing to the Program Files folder can be a problem - in that case it's better to create a new folder elsewhere and install to that, but I'll ignor that unless it's needed. For Victoria 4 and her morph sets (and Michael 4 and his) you need to let the installer run an initialisation routine before you can use the figure; other content doesn't need that. The readme should open at the end, and at least tell you which of your library folders to look in for your new items.