I'm fairly new to Pinterest, and I'm definitely no expert. But I find people are always asking me questions about it. Here is one that they do not have in their help/support Q & A, but I stumbled upon myself and it's one that people always ask me. "How can I change one of my pins from one board to another?" It's easy...
Step One: Click on your profile (upper right corner)
Step Two: In the drop-down, click on "Boards"
Step Three: Click on the Board containing the Pin you want to move.
Step Four: Click on the Pin you wish to move.
Step Five: Click on "Edit" (scroll across the top of the pin and the word "Edit" should appear)
Step Six: In the "Board" field drop-down, click on the new Board for that Pin.
Step Seven: Click on "Save Pin"
And Voila! There you have it!