Robert,
Good luck in your new hobby! Also, welcome to the forum. There is a wealth of information here. Anything you have questions about you can find an answer here. You can either do a search for your info or just post a new topic like you just did.
You will be happy with your Railking Starter set. MTH put their top of line sound and control system in them. The engine will have their newest operating system in it. You will want to run it with a DSC System to get everything out of it.
The most important thing you can do is READ the instructions on anything you buy. Also find a book or two about the MTH DCS system as well as anything on Lionel's TMCC or newer Legacy system. Find any video's that will help you learn either system. All are great systems and allow you to run multiple locomotive's on the same track or layout without any specialized wiring. (Just reiterating what PCRR/Dave wrote above.)
In my opinion, save a couple of bucks and go ahead and buy the DCS system. Your going to eventually buy it anyway. So why buy the DCSRC then buy the DCS system. Also, the DCS system will operate trains that aren't command control. In other words, it will operate your older engines by remotely raising and lowering track voltage as well as control your DCS engines at the same time. You may eventually buy the Lionel Legacy System also. It will also run conventional engines with the addition of a Powermaster or a TPC-300 or TPC-400. I use the Legacy system. All my equipment is Lionel. Just a personal choice. The MTH stuff is great also.
As far as turning radius goes, you should stay with the radius it states on the box. Sometimes you can try a tighter radius than that which is specified. It really depends on the size of the rolling stock or the engine.
Sorry to be so long winded. LOL!
Good Luck and most of all have FUN!! That's what it's all about.
Mike R
