Reply To: Power Button extension to start and safely shutdown the Raspberry PI

Yes, transistors are BC338 (driving the relay) and 546 (other). 33k is fine. You can simply install the plugin on your system, also if you have not connected any hardware yet. The actions of the plugin should have no effect then. On the plugin page, there is also an enlarged version of the schematic.
Pin numbering is the pin number on the 40 pin GPIO connector.
Button pin is set as input with internal pull-up resistor, ready pin as output.