Hey Rocky. There are pay-for (and freebie) flight planning tools that will do more or less what you want, but if you want a simple solution you might look at SkyVector which is a browser based thing in case you haven't seen it. Punch in an airport code (e.g. NZWN) in the form field top left and it will zoom you straight there. You'll see all the high and low level airways and the way-points, VORs etc.
see:
https://skyvector.com/As far as choosing a route goes, I guess you know about the "Standard Route Clearances" documents at AIP? These list the routes usually flown by IFR aircraft from one airport to another.
e.g.
http://www.aip.net.nz/pdf/NZWN_61.1_61.2.pdfThe thing is, SIDs wont necessarily match up with a way-point on the airway your intending to fly, usually the SID will direct you to a specific way-point at a certain altitude and from there you are expected to join up with your cleared/planned route which might mean flying DCT to the next or closest way-point on the airway you'd planned to take. Hope that helps, and if you already knew all that stuff, well, no offence
