Welcome to the gauge Rob, as Ralf said, and I agree, you should read, read, read, every thing you can, before you get started in making the most important decision you will make in this wonerful hobby.... THE SCALE. In which to build your empire. why is it the most important?. Well its that, that you will spend you hard earned $$$$.
In case you didnt get cidchase`s hint he models HO Steam...and his advice on your layout space is a very valid one.. if you put a large table type of bench work in the middle of your space, unless you have arms that are 4' long you wont be able to reach the centre of your layout. to build it in the first place, and if you think you might get out of it by sitting on one side and then building.(and this has been tryed before)will fix that little problem, it wont.. if you run into problems(and you will)later, you wont be able to reach the proble and fix it with out destroying some other part of your creatation...so the type of bench work for your layout is important..The one piece of advice that I can give you, is Take your time...dont rush to get it done....But above all have fun,fun,FUN....
Rob any questions that you may have.... ASK....you will always find an answer here, from the most friendlyest bunch of modelers on the internet.....have a good one..steve