PHP programming forum. Ask questions or help people concerning PHP code. Don't understand a function? Need help implementing a class? Don't understand a class? Here is where to ask. Remember to do your homework!
PHP Anthology Part 2 (that's a book) has a whole section on such things. PHP Cookbook (another book) has about 10 recipes as well. Which reminds me I really must get that book back from my friend before he losses it