its syntax looks quite like C/C++, Java (and JavaScript). So if you've ever coded one of these, it should be quite easy to start with, although there are still differences. Anyhow, even if you've never programmed, you should get the hang of it quite fast. (I recommand buying a book about it, once you're comfortable use resources found on the web).
Once you're decent with getting database stuff (you will probably be starting with MySQL, which there is so much tutorials and books about) you might feel like you know everything about the language. However, if you ever go deeper in PHP and start learning more advanced stuff like Design Patterns, Unit Testing, Refactoring, etc., you will feel like you know nothing. If you ever get serious enough to reach this stage you WILL have to buy books about these.
So in short, yeah it's quite easy to start, but if you ever want to get serious (get contracts, etc.) you will have to spend money on books and it will get hard
