Jonathan,
Thanks for your response I don't understand every thing about this DCC system and  I keep reading about reverse loops and additional amps needed to expand a layout, I just wanted to know what I was getting myself  into before I started this project. I got to say its been a lot of fun tracking down all the information required to do this, I am thinking about taking back the train set for myself. 

Thank's Again

I give my Grandson a DCC Bachmann Train Set for X-MAS. I would like to expand the existing layout with an outer  oval track connected with 2 #6 crossovers on each side of the inner. Other then the additional track and crossovers what electrical items would I need?