Hi. I'm a dad that has absolutely NO model railroad experience. Last year, I bought my son a Marklin HO starter set for the holidays and he LOVED it. I'd like to take the next step of starting a bit of a collection with him as I think the hobby is great both for creativity and fun as well as for learning how to build and wire stuff. Unfortunately, with the demise of the corner hobby store, there really is no place I can go for help on how to really get started. The place I bought the starter set literally closed a few weeks later. Is there a guide/book that anybody would recommend that would explain what I'd need to get for the "next step" in our adventure? I'd prefer to invest in hardware that can grow with my son while realizing that a 6 year old won't have the patience for tons of bells and whistles.