This is the person you're spending the rest of your life with, so be willing to tell them everything. Be honest and do not be afraid. If you can't tell the person you're spending the rest of your life with - then who can you tell?
The key element in good communication is honesty. If you're honest when you communicate with your spouse, this will help them understand what type of communicator you are and how to approach you on various situations in the future.