Tim - if you have a PPL then you already know all you need to know to do this.
Get the VFR charts, draw a route which is outside controlled airspace, work out the MSA for each leg, work out the speed/performance stuff, and that's it. You navigate it any way you like, including (the easiest way) GPS.
Depending on the plane, you may need a fuel stop.
Before the flight, get weather, notams, and call the destination(s) to make sure they are open, have avgas, etc.
I am sorry if this sounds unhelpful but if you cannot do this already then your PPL instructor(s) should be shot
You may also wish to take additional oil
Only if flying a Spitfire which has never been serviced