Hi Chris
Congratulations on the scope purchase! Plus me as well for a red dot finder. It is one of the first things I bought. Please don't worry about eye pieces and barlows & such just yet. Just learn and enjoy that scope first.
I used to have a 6" dob and it served me very well from my light polluted suburb. You can make out the bands on Jupiter, the rings on Saturn easily, nebulas, galaxies, globs, everything. The 6" is considered to be the entry level "serious" scope, so you will not be disappointed.
The only other things that I could suggest right at this point in time would be a planisphere which is incredibly helpful in learning and finding the night sky. They sell for around $15 from most telescope retailers. Also, the Astronomy 2010 book is a great starter book. Even though the calender of events is just about finished, there is a lot of useful information within it. Because the year is nearly finished, most places I believe are selling this book for only $10. I'm pretty sure Andrews Communications on-line do as well.
Actually, I just thought of something else.. though a bit expensive, but I can't speak of them highly enough. It makes all the difference to a good comfortable night's observing. A stellar star chair, sold through Bintel for $179. Expensive I know, but completely worth having one. It's narrow and folds nice and flat for storage/car, and height adjustable.
https://www.bintelshop.com.au/Images/Stock/7201.jpg
All the best on this terrific new journey of discovery - our amazing & majestic universe awaits you. I bet you can't wait for your scope to arrive!
