Preparing for the CompTIA A+? Where to Find Good Practice Questions?

I am studying for my CompTIA A+ certification while working a part-time help desk job The job gives me practical experience, but it also uses up a lot of my study time during the week I feel I understand the concepts from the book, but I am worried about the style and difficulty of the actual exam questions I have been looking online for reliable CompTIA Questions to practice with Can anyone recommend a source for practice tests that are close to the real exam? I am looking for questions with clear explanations for the answers, not just a list of items to memorize Where did you find the most useful practice material?