You should learn PHP quickly because it is currently the programming language of choice for web applications. This being said it is in high demand and will be for the next foreseeable future. This is because it is easy to learn, fast, and very flexible. PHP will run on any computer that it is installed on. It is cross platform and requires no special tools to program in it.
By learning PHP quickly you can become a professional PROGRAMMER that is in high demand right now. Many of the top PHP programmers right now are charging a lot of money for their services. In this time of economic need does that not sound good. Now imagine you could learn the basics in 17 hours. That would put you way a head of the pack.
PHP is easy to learn because it is readily available and very flexible as stated earlier. There are many resources for learning PHP. The best advice I can give you starting out is to just do it. The more you code the better you get at it. You will learn all the tips and tricks and become familiar with the language. There have been many books written about PHP and I will tell you that the online manual is probably better than 90% of those books. Check the manual any time you have questions. As you pick up more skills you can diversify and program more than just PHP. If you can learn PHP quickly then there is no reason afterward to learn HTML and MySQL so that you can offer more services and make better web applications. Both of these mean higher costs per services and that helps you out.
We are in the information age and computers are not going anywhere. With sites like Facebook and twitter building on PHP you can easily learn PHP quickly and get in on the explosion of creativity. Now there are several ways to learn PHP. You can buy book after book and do what they say. You can take courses at community college or university or you can learn at home. I will tell you that learning at home by just doing is the best way to learn anything.