Ajax!!!

Today I started to learn Ajax. Actually I learn most thing from web but I kept a book too from whick I can learn the basics. Somedays ago I bought a book on ajax name “Professional Ajax” by Nicholas C. Zakas, Jeremy McPeak and Joe Fawcett and publisher is wrox. I don’t know who this book is but I think I will get the basic concepts from it.If u have any suggestion about  ajax like which book is good or any web link from whick I can get better help about this plz let me know…