The workplace is tricky. The balance between getting along and sharing but staying private and not too personal is not easy. Sharing you went to great place on Friday night with the one you love, but sharing the reason you're no longer together and why is too much. However, there are work incidents you want to talk about with other people who can relate to what you're talking about. By relate I mean, the environment, the type of people, the workplace climate due to the economy. Your spouse if fine, but still it's another sex's perspective. Family kind of gets it, but they are so Team You their opinions may be a but skewed; as they should be. Enter your friend, but not all of them.
On your friend list are a lot of people who are there for different reasons and needs in your life. The friends that are best suited to help you talk through some work incidents and strategic moves are those that have more similarities than differences. Like you, they are looking for a safe place to speak openly about work, the people and the place, and know the conversation will not leave the table. Not only will it not leave the table, but will not be spoken of again unless you bring it back up. These friends do exist on your list. If looking at your list you can't choose at least three people you have bigger problems than your workplace.
These friends may have been in your life since childhood, or only a few years. They definitely have been with you in moments of life changing events, both in your life and theirs. My advice is to meet with this group at least once a month. If you can't physically meet, make a not on your calendar to call each of them once a month. It's this connection with true safe open people that will give you strength and clarity to continue on to your goals.
Everyone needs a safe place to be open and honest to speak about their job and the people there without fear of being judged or that the conversation will be leaked out. Find your group and keep them close. They are a part of your career goals plan.