Advice for a newbie on DNK

I am relatively new at buying and selling shares although I bought STB years ago and have hung on for quite a while. As a lot of you talk about accumulating more I was figure you buy more in small packages. I was wondering whether you use big brokers like Patersons. Are sites like Commsec worth trying. Any tips on reducing commission costs would be appreciated.

I am hoping we are in for a hell of a ride with DNK.