Reading instruction is a component of the language arts curriculum that should be introduced across multiple subject matter content. Children ultimately have to understand what they read in a variety of textbooks, not just as part of a language arts class. Yet, reading instruction begins long before formal education begins, especially for homeschooling parents and educators.
If your child is used to doing a worksheet or two, they will be able to do this quite easily, and will understand that they need to complete the task before they can move on to the next activity. Worksheets also help your child to learn how to follow instructions, and teach them about following rules.
Worksheets also, when used properly, provide both the students and parent / tutor immediate feedback as to the child's progress. This means they can be used to point out areas where the student needs further reinforcement.
While there are many preschool worksheets available, some are more useful than others in terms of versatility. There is a lot more to school readiness that just knowing the alphabet and counting to ten.