I've read a few hundred books on business and personal finance, and I think this book provides the best introductory advice on investing:
A Random Walk Down Wall Street
If you want a shorter book, this one is good too:
The Little Book of Common Sense Investing
Caveat: I'm not rich (yet), so you may want to take my advice with a grain of salt. Your best choice may be to find someone who is rich and ask them how they did it. Make sure you find someone who actually has a high net worth, not someone who just acts like it by driving nice cars and spending lots of money.