Gidday, [#welcome] to the forum.
Well a simple question should deserve a simple answer , but your question is anything but simple and depends on several factors.
An admirable aim, but how old is your son ? Is he going to be an active participant, or is this an excuse for Dad to enter the hobby? [swg]
What space do you actually have? What may be small to you could be an empire to another. Anyhow here’s a link to small layouts…
http://www.carendt.com/ …and here’s a link to a forum members site, well worth a read
I model in HO, suitable for my clumsy hands and dodgy eyesight besides I’ve been quietly collecting HO locomotives and rolling stock for quite a few years. . However when you look at these threads, if I was 15 years younger I might reconsider…
http://cs.trains.com/mrr/f/11/t/195425.aspx?sort=ASC&pi314=1
http://cs.trains.com/mrr/f/11/t/212393.aspx
You asked a simple question and all I’ve done is possibly confuse the issue, [sigh], but the best advise I can give a newcomer is to keep your wallet firmly in your pockets and research, research, research, but also bearing in mind that procrastination only achieves frustration.
If my questions are answered then hopefully you’ll receive more considered advise.
Have Fun [:D]
Cheers, the Bear.