SEO Books will be outdated very quickly. Your best source is to first have an excellent understanding of web development, html, asp, design concepts and design standards.
You need to take online courses. These can be expensive from the top online schools but worth it in the end. You need to sign up fro the best feeds, ezines, forums that are online.
You need to be familiar with Google webmaster guidelines, ppc, link building, sem and social networking.
You have to know how to market yourself as a professional. You best bet is after training find a mentor who can guide you and teach you the ropes.
Learn how to search for what you are looking for as well. If you want to do SEO and SEM, then know how to find best information online. There are many and what I feel is best you may not based on your time, budgets and so on. So do some heavy research and reading as that will help you grow as well.