You have latched onto a great and well discussed topic and there is too much to say on a short thread. Have you done a search on this topic in the archives: Look at the upper right corner for the search function. Simply type in a key word and your day will be filled with reaking great ideas.
Base prep is the most important in laying surface track. As you will see, there are many ways to approach your base prep, however they all have a common theme, proper drainage, use of the correct ballast and most importantly making sure that the track is level. My system will be elevated so my approach is very much different.
Craig, check the website's questions forum for some tips on how to tackle the search mode. Make sure that you are in the forum which would most likely have your answers etc. Keep your keywords simple. And yes to go back I've found that I need to retype in my key question.
I'm sure that a moderator can chirp in here with some quick tips.