You can access FAA air traffic control documents at faa.gov/ATpubs/. The one that you will be interested inis 7350.7 “Location Identifiers.”
The 3 letter codes in the routings are VORTACs.
The 5 letter item in the example given (DUNKS) is an intersection formed by radials from 2 VORTACS.
The item at the end of the route (BUNTR1) is a STAR (Standard Terminal Arrival Route).
All of the above can be decoded using 7350.7 Additionally, you can download the actual STARs by clicking on the resources link to the left of any FlightAware screen and then picking the arrival airport.
“J” routes (e.g. J70) are high altitude routes. I believe the minimum altitude for these is 18,000 feet. “V” routes that are below 18,000.
DUNKS J70 PMM J547 OBK BDF IRK J96 GUP BUNTR1
decoded: from DUNKS intersection take J70 to PMM then J547 to OBK. From OBK fly direct to BDF direct to IRK then take J96 to GUP. At GUP use BUNTR1 arrival. Use 7350.7 to decode the abbreviations.
DUNKS J70 PMM KG69K RBA KK54C CIM ZUN BUNTR1
from DUNKS take J70 to PMM then KG69K direct to RBA then KK54C to CIM then direct to ZUN and then use the BUNTR1 arrival.
I’m not familar with KG69K and KK54C. If I knew what the departure and and arrival airports and aircraft type were, I could probably figure it out.
naco.faa.gov/index.asp?xml=naco/catalog gives a brief overview of different charts available. Doing a quick Google search, I couldn’t find anyplace that has online charts.