http://awoiaf.westeros.org/index.php/House_Estermont/Family_Trees = There is a Lord "Estermond" which should be Lord Estermont.
http://awoiaf.westeros.org/index.php/List_of_characters = This page says "Arthur Ambrose, Lord of Ambrose and sworn to House Tarly". A source isn't given for that statement and I haven't seen it stated anywhere else that House Ambrose is sworn to House Tarly.
There are a lot of characters missing from the list of characters index as well, such as Cerissa Brax, Teora Kyndall, Cerelle Lannister, Alysanne Farman, Tywald and Tion Lannister, Alys Stackspear and Ella Lannister. Malora Hightower and Humfrey Hightower as missing as well.