Find free "U" values for heat exchanger design in this post.
What is a "U" value? If you've taken any classes in heat exchange, you probably are familiar with the simplest heat exchanger design equation:
Q (duty) = U (coefficient) * A (area) * deltaTlm * F
Where deltaTlm and F depend on exchanger geometry and are explained in any heat transfer text.
The trickiest part is the "U" value, where you have to find a co-efficient that fits the type of heat exchange you are performing. Here are some free resources I have found, if you don't have a book like Perry's or Rules of Thumb to help you.