I have read the Spring books and know the basics about AOP. I want to learn Spring Roo but I don't know AspectJ and annotations.
Do I need to learn those to get started with Spring Roo?
You don't have to, as Roo manages all the AspectJ artifacts for you - the generated .aj files. However, knowing the underlying AspectJ concepts will help with what Spring Roo/Spring in general, is doing under the covers - Spring Roo Critical Technologies: AspectJ.