Magick works as well as you believe it will. Some spells will work better for some people than others. Unlike in the movies, there are no ancient incantations that suddenly make magick work. Just like prayer, it is best when you write your own spells.
Magick should never be used lightly, for fun, or to show off. Magick is sacred and should be treated with respect (but, let's face it, you wouldn't be here if you didn't want to know what it could do, right?). Most importantly, magick can be used to heal and for protection.
It can also help with money problems. Magick won't make you rich or magickally summon up a new sports car. Like I said before, magick doesn't cause quick drastic changes. If it is an emergency, however, magick can help you to get just enough money to get by. If you are aching to get into a certain school, a little charm can help you on your way. Sometimes simple things, like helping with chores, keeping your garden healthy, and making your room feel comfortable, can be achieved with a little magick.
Remember, however, that you should never be greedy using magick. Greed will cause spells to backfire on you, as will hatred, anger, and the desire to harm another living being. Greed means asking for money when you don't need it (getting something you want is not a necessity), or trying to make someone do something you want using magick. There is a big difference between need and want. People need a home, food, love, safety, happiness, and good health. Wants are things like popularity, material items, expensive clothing, and a fancy house.
Though it may be tempting to try and use magick for greed, it just won't go your way. Test it if you like, but I promise you, the repercussions will probably be more than you are willing to deal with. Magick works on keeping things in balance and can be used to do so. You must give in order to receive, kill to live, love to be loved, and do good in order to receive good things. Always remember this.