I would start with "A Witch Alone" and then with "Wicca: A Year and a Day". Then go on to "When, Why...If" and "Before You Cast a Spell".
By the way, the term "Year and a Day" is not meant to be taken literally. It actually means until some time in the future. Many Wiccan Trads like their students to study for at least a full turn of the Wheel (which takes a year) so that they can be certain that they are truly dedicated to this path and it isn't something about which they might change their mind. This is a life-long journey, don't be in a rush to do things. Take your time, think about what you are doing, and follow your heart.