lsusb -t -v

Gives device numbers and ports but the plain lsusb gives device name
along with device number.

The two should give you all the information you require :-)

Note: lsusb -v will give you far more information but it's a case of
sorting out which bits are relevant

I'm using a Make makefile that wants to know what USB port to use.
Sometimes it is /dev/tttyUSB0, other times it is /dev/ttyUSB1. How can I
tell the Make makefile which one to use?