I basiclly just want to be well rounded with php in case I ever recieve a customer who needs a script done, I can just do it from my head and hand it to them without going crazy, or hassling over a script. It also lets me make more money and lets me expand my business to attract more customers.

As to how deep I want to go question. I want a book to go into detail for example:

If they are talking about functions. I want the author to do more than just "this is a function and this is how it looks like, ok next we talk about cookies" thats what I'm trying to avoid.

By the way, the Advanced PHP book, is that too advanced for me? Is it just the title of the book?