Dream,
Taking an inventory is step 4 - "Made a searching and fearless moral inventory of ourselves". My sponsor told me to pay close attention to adjectives and adverbs in the BB. What kind of inventory? Moral, searching and fearless. Easier said than done.
The BB tells us how to do this in the chapter "How it Works" on pages 64-71. It won't hurt to read this even before you start the real work with your sponsor. There is also lots of 3rd party literature and workbooks on step 4 that may be useful. Google is your friend here. There has probably been more written about step 4 than any other step.
Good luck and keep posting.