If I want to see what I am wearing, I do TAB (brings up star-menu), D (goes to items) and select 'apparel'.
I get an alphabetic list which isn't really that useful to see what I am actually wearing.
For example, when I found a ring and am considering wearing it, I want to check that it's not worse than what I'm wearing now.
When I'm hovering over the ring, I have to run over the entire list to see if some other 'active' item which I'm wearing might accidentally be a ring, and then compare both.
Note that for armor, it does say what the effect will be on armor rating, and I've seen the triangles that suggest the best equipment (but they seem to not take enchantments into account, or atleast not those that suit my playing style).
Is there an easier way to see what I am wearing, which slots are empty and for which I have items I can equip?