1. Click the board icon in the post
2. Click "set up position" and set it up (make sure the right color is next to move)
3. Click "Moves" and make the right moves that the solver has to play in order to solve the puzzle
4. Under "Theme" check off "Puzzle"
5. Click the "Insert" button and you're set!
I have seen people inserting puzzles in posts (ones that have white to move or black to move, like the daily puzzle). For future reference, how is this done?