Francie, they tell you one carry-on and one personal item, which they usually define as a purse, backpack, or briefcase. Unless it's a really crowded flight or one of those tiny regional jets, that usually just means two items.
Now that most of the airlines are charging for a second bag, I'm going to have to carry on more than usual. Typically I take a tote bag or backpack with all my purse stuff, books, and laptop. Now I'll have to also carry on a small suitcase or tote bag with my toiletries, makeup, hair dryer etc because I can't get all that plus my clothes and still stay under 50 pounds in one suitcase. We're traveling to New Mexico for nine days in a couple of weeks and this will be a challenge!