The wiring schematic depends on the guts of the 3 position switch.
The switch you described appears to have a simplistic center off position.
You have the 3 connections for the left pole and 3 connections for right pole.
SO, power goes into the center of both poles. For the taxi (call it left pole), a jumper from bottom to top and a lead (from either bottom or top) going to the taxi light. For the landing light (on the right), a lead from either top or bottom. Depends on which way you want the switch pointing when both are on.
You will have center off, down taxi and up taxi + landing (if you choose to do it that way)
There are other 3 position switches that are called progressive transfer switches that can be wired such that down is off, middle is one function and up is both.
The Aeroelectric book is your best guide for this.