I installed open garden and get "unable to start OG tethering, please try agian!"
I'm a rooted newbie, and this is all new to me. Any ideas what else I need to do?
I have Barnicle installed (with no problems) but I was told that, wireless tethering was the way to go.

I have the same problem but with the 'Wireless Tether' app. Yes i am rooted.

double check which app you download from the market. Wireless tether for rooted will do the trick.