Just a small correction that might clear up some confusion. Individuals become LEED accredited. Buildings, developments, and homes become LEED certified. An accredited professional is the one that dose the necessary paperwork so that the building can be certified. This would be an accreditation that an architect or a construction management professional would receive. The organization that oversees the certification of buildings and accreditation of individuals in the U.S. Green Building Council
To be certified a building receives points for different design or construction criteria. For example on the construction side you can get 1 to 2 points for Construction Waste Management. You receive 1 point if %50 of construction debris is recycled and 2 points if %70 of construction debris is recycled. Part of receiving the points is doing the paperwork to prove that you meet the criteria. On the design side you can get 6 points for Public Transportation Access if the building is within ½ mile walking distance to a subway, or ¼ mile from a bus stop. Depending on the # of points a building is certified Platinum, Gold, Silver, or simply Certified.
As far as benefits to certification, it can be used as a marketing tool. The construction cost of a LEED building is more, but over the life of the building those costs are offset by decreased utility and management costs. I believe that the breakeven point is about 7 years.
There are many municipalities that are requiring buildings to meet a certain LEED standard, and many government building are required to meet certain LEED certifications, so it is something you should at least be aware of. This applies only to commercial buildings as I have not here of any requirements from a government on residential homes.