As Burkhard says, some screen shots of you ../Plugins/ folder and toolbar menu would be very useful.
Do you get any error messages when starting Sketchup? If so, then what?
If you open the Ruby Console form the Window menu and type
octane + <
enter> key does anything happen ?
I suspect you simply haven't got files in the right locations...
You say about putting files intot he 'Sketchup' folder -
no files go there thay are in ../Plugins/ or sub-folders within it.
Show us the folder screen-shots etc...
It must be solvable...
