Perhaps the simplest to build post and beam frame, and the one easiest to get code approval for, is the one described in a previous blog post about Post and Beam Hardware. The standardized hardware used in this method takes all the guesswork out of the process and ensures a strong structure. However, that system is not suitable for every situation. Some people prefer the beauty of traditional post and beam where the frame is exposed. Traditional post and beam construction is much slower and requires much more skill and tools than joining the frame with standard hardware, but the results can be worth it.
Knee braces in the post and beam frame provide lateral support to resist wind loads and prevent racking of walls. Knee braces improve shear resistance and help transfer lateral forces in the upper part of the building to the foundation. Each post typically has at least two knee braces in opposite directions so one is always in compression. Research post and beam construction for further details.