Hi Jackie and welcome to IIS!!
Well done on getting out and using the binos. THere are lots of objects that can be found and enjoyed with a pair of 10x50 binos. Scope wise $300 is a fairly limited budget so the main object should be to get the best "bang for your buck"! Smaller dobs are the way to go. Please avoid the really small table top ones. They are in a lot of cases gimmicks.
A new 6" dob can be had for a bit over $300 at Bintel or you can shop around. 8" is definitely better but you will be looking at at least $500. The main commercial models you see around are all pretty good (GSO, Bintel, Skywatcher, Saxon) it often comes down to price and accessories.
A good basic guide is this
http://www.bintel.com.au/Accessories...oductview.aspx and I can recommend these
http://www.bintel.com.au/Accessories...oductview.aspx as a great starter set of charts. I have my copy I bought 5 years ago and still use them nearly every night to get my bearing around the constellations and the brighter DSOs. I laminated mine and put the in a folder to protect them
Get a red headlamp to preserve night vision and enable you to read charts. Also try to spend time naked eye observing. It is fun just tracing out the the Constellations and seeing the various open cluster and DSOs that are visible without a scope.
Cheers
Malcolm