I recommend the 3 ways that I got most of my experience.
First, the first site I every built was as site devoted to my hobbie. Doing this has unlimited potential in what you could learn. As you can go as far as to build your own forums and blog scripts. As well you can make exclusive content for members and build some basic login security. As well you can get a grasp of SEO (search engine optimization), as it relates to web design, before you need to know something about it on a more important project.
Second, if you happen to be involved in any type of charity work or know someone that runs a non-profit maybe they need a web site or even their current one is way out of date. Offer to try an remedy that need for free. Here you have to be a bit more causious as what you may like to try and do verses what they want can vary alot. As well make sure you keep a backup of any original site they may have in case it all goes horribly wrong.
Thrid, if you know anyone that owns their own business but does not have or has a poor web site try to pitch them the idea of increasing there business and you will do it for free. Or maybe a 1% commission on business they get from that web site (if your skills are fair). To do that you will need to set a plan in place for tracking new customers. And here again you have a chance to learn another totally differnt side of web design. As well you may learn a lot about running a business which will help you if you decide to ever sell your sevices.
I think real world experience is way more valuable for learning than just doing theoretical design out of a tutorial. Becasue what you need is never like any of the examples or tutorials you see.
Also, a tip for saving you a ton of work down the road. Make sure you keep every last bit of code you do design. Even if you design something for a site and then decide you do not want to do it that way, keep it. I can not tell you how many times I have saved something I did not use and later used all, part, or a modified version of it on some other site.
I see you have been reading some books. I highly recommend a good pile of them siting on your desk. I currnetly have a HTML quick reference, 2 javascript books, one CSS quick refernce, and a php book on my desk plus php.net is always running.
Well hope that gives you some ideas, good luck.
