Thank you very much, I will look into all the suggestions.  We are pretty much going to go with the HO scale, but the suggestion of non-electric has some definite plus features.  Are there non-electric HO scale trains?

Size is a really big issue, as it will be mounted on a fold down on the wall, in a bedroom.  4x8 won't fit, unfortunately.  I am of the opinion that good track is necessary, too.  Tyler is young... Only 3 but very careful, thoughtful and it will not be accessible to him when he is not supervised.  So most houses, things like that will have to be movable to be able to close it up.  It will have a 3 1/4 inch lip along the edges, the transformer will be attached to the table.  I know he is young... but he has such a keen interest in trains!  We live in western CO and we often have to stop along I-70 where the train tunnel can be seen from the road, to see a train coming through.  Never saw anyone so thrilled to be "stuck" at a train crossing.  LOL 

Thank you all so much!  We are only doing a small 4x6 layout, but I wanted to use the best base I could afford so as to reduce the number of potential issues as we use it.  Are there any suggestions or layouts anyone would be willing to offer for us to use?  This guy would sell me one... I found it a bit disgusting that someone who claimed to be an advocate for model train hobby enthusiasts wanted to sell me a plan for a young child's first set.  I don't have the guy's name, when I asked for a card he gave me one for the store.  I handed it to him for him to put his name on it and he said anyone in the store was as good as another.  Whew... Sorry to keep going on this guy, it just really yanked my chain.
Tyler's layout will have an 18x24 inch hole cut in the center so he can access everything.  We'll fill it in later if he wants.  I could use a suggestion for a good basic engine that is reliable.  Part of what we were given includes two diesel engines, but since the guy was a rude turkey he never looked at them to let me know what I had.  I could take photos of them if anyone would want to help us in this direction?
As far as track, my understanding is the silver/nickel is the best type of track?  I thank you all again,
Laura & Tyler   

We are trying to put together a HO layout for our grandson, and were given a huge supply of various track pieces.  Some were still in the original packaging clearly saying "Bachmann" on the package.  Looks to be standard, tack in place track requiring joints and such.  While at a local hobby store I tried most unsuccessfully to get some help from the guy at the counter and was basically scoffed at with a snide comment to every question I asked him.  I told him I had the track, still in the package and was told in no uncertain terms that I was an idiot and Bachmann only made track with a base attached.  I finally walked out disgusted resolved to never ever enter Hobby Hut again and decided to ask this forum if Bachmann indeed never made "real" looking track, just the rails and ties, NO base.  I have some of the EZ Track, it is most definitely different.  I simply hate being treated like an idiot just because I am not well versed in a subject.  He said all the engines are the same, some cost a lot more and do no better.  If it runs, it is the same as any other.  I would really appreciate some real help, if anyone would care to educate me?  Oh, the track was purchased by the original person in early 1990's, if that makes a difference.