Since you mentioned your interest in Proto-48, the thread from the 2 rail forum below may be interesting to you. Proto-48 is very much a modelers world in O scale and something you may enjoy. As you obviously have an interest in scale equipment as well as scale operations, you may consider putting your post in the 2 rail forum. Proto-48 is very different from 3 rail O and also much more challenging (and to some more interesting) than the standard 2 rail wide gauge 5' rail spacing that is the accepted standard in the US.
The best advice I've seen so far is to get some used scale starter cars and locomotive and experiment. Used O scale is often very affordable. Best of luck to you!
