Log built patio cover questions for mounting and construction

[Jensming]

I'm looking to build an outdoor covered patio area about 12 x 20 from green timber I plan to cut. I've never done this before and am reading up on how to prepare the logs. But, I am finding mixed input on how to secure to the ground. Some say concrete is best while others suggest you should mount above the concrete with some type of bracket to avoid decay of the wood and shrinkage within the concrete does anyone have suggestions? Anyone have similar projects you've done I could see for ideas?