First, you really can't begin to have a good basis for Catholic doctrine without a copy of the Catechism. When I was in late high school and early college, I really began searching for what I believed, and part of that was finding what Catholicism was really about. I read through the Catechism during one summer, and I was really amazed by what I read there. My faith formation was really very poor, so I really learned an amazing amount by reading the Catechism.
On the other hand, if you are a mother with a limited amount of time, and often lacking in brain cells due to sleep deprivation, you might not be quite up for a cover to cover read of the Catechism. We now have the Compendium of the Catholic Catechism available, but I actually haven't read it, so I don't know if it would fit the bill or not.
What I have read, and can easily recommend, is getting a copy of the old Baltimore Catechism. A few points are outdated, but I found it very easy to understand, and with clear explanations of points of faith. For example, on the saints, it says:
After I read that, I moved on to every Catholic's favorite apologetics book, Rome Sweet Home, by Scott and Kimberly Hahn. What can I say, it's quick and easy read, it's funny and touching, and it hits all the main topics everyone has questions about. You can read Scott's conversion story online, but the addition of Kimberly story makes getting the book worthwhile. This is the book I loan to all of my moderately Catholic friends and family.
As I began to wade into apologetics, I often reach for Dave Armstrong's A Biblical Defense of Catholicism. This book is really excellent for understanding the Biblical basis to various Catholic doctrines. It is written in an easy to understand manner, and while it is longer than Rome Sweet Home, I still think it would pass the new Mom sleep deprivation test. Many of the points he made were in agreement with what I learned at a state University, so I felt I could trust his research. For example, he gives a timeline for when various books were considered canonical for the New Testament, and even lists the source for the information (i.e., Eusebius).
Along similar lines, is The Catholic Controversy by St. Francis de Sales. St. Francis was sent as a missionary to the Chablais region of France, which had been converted to Calvinism. However, the Calvinist ministers had warned the people not to listen to his preaching. Instead, he printed pamphlets, which he slid under doors at night. After four years, 72,000 had converted back to Catholicism! Because of the date these were written, the language is at a higher level. I really enjoyed reading them, though, and his arguments were very simple and logical. Because of the audience, he relied heavily on Scripture based arguments, but also appealed to the Fathers of the Church at times. Some parts are outdated, such as the section on why Mass can only be said in Latin! I especially enjoyed his defense of the primacy of Peter.
I also bought The Essential Catholic Survival Guide, which is basically the Catholic Answers website in book form. It includes the essays about Catholic doctrine, but also the entire section of the Anti-Catholicism essays. Hunting the Whore of Babylon, Is Catholicism Pagan?, it's all there. I love the internet, but I like being able to read from a book, too. Especially when my husband is on the computer, or if I want to be able to loan the Catholic Answers website to someone.
Finally, I LOVE my Navarre Bible, Reader's Edition. The three volume New Testament is the perfect size. It isn't too intimidating to read, but I get paragraphs of Catholic exegesis for almost every verse. The notes are often quotations from the Fathers of the Church. I love reading sections from homilies that were given hundreds of years ago. It's like the Greatest Hits Bible. I recently received the final volume, which includes Revelation, as an early birthday gift, so you can look forward to more tidbits from there in the future. Especially if the Whore of Babylon comes up again. (And it will!)