I think the docs they provide are helpful. https://docs.hak5.org/hc/en-us/categories/360000979313-LAN-Turtle
I do think the guide is the same for the 3g and regular turtle.
I have found a lot of uses for my 3g and ended up with a second. I think they are great.
Also I have found that when I have a specific question, the people here seem very willing to help.