To find content in Studio is sometimes very tricky as the structure of studio is not so clear as it is in Poser.

Cough... Surely you mean easier for you? I Personally prefer DS's methods of handling content storage, where everything isn't a hack on a Pose preset and shoved in the Pose folder. ;) Using both the Smart content and Content library tabs together makes life pretty easy.

In Daz Studio content you can use either the content library or Smart content to find things in your library or both together. The smart content library tab uses metadata and associations to bring up relevant content to what you have selected in the scene and from there you can further drill down by type. The content library tab is closer to the poser library where most things are drilled down to from the top of your content library.

Poses belong in : /People/Figure Name/Pose/Pose Set Name

Ubershader or Iray uber base shader is part of the base Iray lights and shader set for 4.8 and can be found: /Shader Presets/Iray/Daz Uber This folder also has around 50 other Shader examples for Iray including car paint and metals.

Alternatively using smart content.

Poses Select your figure and select poses in smart content and all of the compatible poses for that figure should be displayed in smart content.

Shaders Select your item and its material surface. Then select materials in smart content and Default Lights and Shaders for Daz Studio product and the Iray Uber base should be at the top.