Answers

Being that this is a saftey first and homeowner's insurance second question, a Licensed Electrician in your county/township is the best way to go. Breakers tripping can be one of many issues from, just a faulty breaker, to improperly installed or overloaded circuits. NEC is nationwide but county codes/variances can be more stringent/specific in residential electrical. Electricians are not cheap but this is an area you don't want to take any shortcuts. Ensure you see their license and make sure the work gets inspected prior to energizing your home.