I recommended this book in another thread and I'll re-recommend it here.
"The Only Investment Guide You'll Ever Need" - by Andrew Tobias. It's less than $12 on Amazon. My Mom and Dad got it for me one year for Christmas when I was still in high school. During college and grad school, I really had no money to invest, but now that the end of grad school is near, I read the book again this past weekend.
It's really good. DaveSimmons is right, "playing the stock market" can be fun, but for long-term investing, it's better to take the easy way out and go for no-load mutual funds. The book is very easy to read (I read it in a day) and offers very good advice.