Howdy Dennis, and welcome to the sledding club! (Watch that first step, its a doozie!)
Being that youve not roasted before might I suggest you try roasting single origins as a start? This will aquaint you with the flavors of the different coffees and will allow you to more easily roast and figure out the process. Different beans roast at different rates and roasting up a blend can be can lead to some issues. Better to eliminate as many variables as possible until you become more familiar with the roasting process and your equipment.
Start out roasting single origins and tasting them. Then make up blends post roast. Roast the beans as SOs and then blend in small lots until you find a combination you like. :)
Java "The roasting fool" phile