Hello Hal,
I advise you to start right away with a digital controlled system.
The advantages are:
1
The most great advantage is the simple wiring: you only need one wire from your computer to the track.
Often people complain about conductivity of their track and decide therefore to go for battery power and Radio Controlled functioning. This is however absolutely not necessary: the only thing you have to do is using Molycote Copper Grease mixed with some evaporating dilutant in all your electric connections. Not only the track connections but all other electric connections too. This keeps all weathering out of your systems for many years. My own track already functions more than about 10 years!
2
When using a digital system there is a continuous Alternating Current AC power of 24 Volt on the track.
The computer generates a digital message, to all users having a built in decoder, which is generated depending on the user settings on the handheld controls. Besides the Digital Decoders in all locomotives, the constant 24 Volt AC also enables to power all electric functions along the track and the lights in your rolling stock with a constant voltage and thus constant light level. In the case that there is a Direct Current DC wanted, for instance when using LEDS to minimize your power consumption, you apply a small current rectifier.
3
The next great advantage in terms of simplicity is that all your points and other operating equipment can be connected directly to the track. No more long wiring to switch banks any more!
4
So far my view on this, and i hope i succesfully explained the advantages of the digital system to you. However in case you are interested in more explanations you can read a lot more about this subject in our book "Our Model Garden Railway" available at Amazon.