Is it possible to group Layers together? If so how? I know how to make layers and groups.. but can I group layers, like how in Photoshop you can make folders for layers?

Layers are actually groups.

Use object's panel (ctrl+shift+L or Object > Layers and Objects).

There you can select one layer, hold ctrl key to select another and press ctrl + G or do object > Group

Inkscape also supports sub-layers, via drag & drop in the Layers & Objects dialog.

Note that they will have typical foreground/background (Z-ordering).

A method to select various objects that will not change the Z-order, is to assign css classes to layers.

Css selector dialog might be broken in Windows... I need to test on other machines.  It seems to work under Linux, as seen above.

One required trick: to select a layer as if it were a group: click a second time on the layer (in the object & layers dialog), not a double click... a slow second click.

thanks.... Ctrl+g works.. I was stumped as it dose not appear to be in the context menu when right clicking.

Anyway, got it working now.. thanks!