Go to barnes&noble and pickup a book. I just finished my A+ this february. I would definately suggest picking up an updated book and reading it. Taking the practice problems, and reading some more. Remember when purchasing / studying to ensure that the material is of the 600 exams, they are still selling some books out there that are for the 300 exams which are now outdated.
Remember the new (600) exam requires two separate exams depending on the route you take.
My only advice would be to know your stuff, they won't just ask you what a DMA or IRQ is, they will give you more situational questions. It isn't just enough to know the speed of USB 2.0 compared to 1.0, you have to be able to impliment it within a certain scenario.
Hope this helps - after lunch I will let you know which book i bought and read.
Mike Meyers was the author for the book i read.