Idea Miners: The Lost Lake Dig by P. W. Cross was a good book and I think that everyone who reads this book will like it as much as I did.
"Idea Miners: The Lost Lake Dig" by P. W. Cross is the story of a lonely boy named Joey who, in the year 1750, meets a mysterious man who leads him to a fantasy world filled with new, as of yet unthought-of ideas, which appear in the form of little balls of light. When Joey enters this new world he is delighted to find that his old friend Ben (who had moved away before this book begins) had also found an entrance to this world. But when the high council asks the two friends to go on a dangerous mission to find a "gusher" (an as of yet undiscovered, very important idea) the two are almost forced to go on the mission. If the gusher is not found and saved, it will fall into the hands of the evil trolls and be lost forever. They were excited to find that a long time in the new world was only a little while in their own world because they would need a lot of time to complete the mission. With some dwarves, a seer, and Joey's dog, will they make it through the troll infested mountains to safety and a job well done?
The world Joey found is very important to his real world because without it there would not be any new ideas. Ideas, both big and little, bubble up from this fantasy world through secret passages to the real world for "harvesting." The little balls of light float around in the real world and will sometimes crash into people and get absorbed (this process is called harvesting). For example, a ball of light containing the idea of matches crashed into someone and poof they had the idea contained in the ball of light (matches have not been invented in Joey's time, so when he saw them in the fantasy world he was quite shocked).
This strange world has dwarves, trolls, and many other mythical creatures with special powers. For example, the seers can "see" the idea inside the gusher so it can be properly released to a person able to use the idea. Other powers include the special (if uncanny) ability of miners (extra-tall humans) to find gushers and other large important ideas, and that of dwarves which isn't really a power but more of an instinct that helps them to build tunnels, avoid dangerous tunnels, and help miners find gushers and other important ideas. The trolls are stupid rock monsters that live to terrorize and eat the people and dwarves of this fantasy world. These trolls would also love to snack on Joey and Ben.
I would recommend this book to people who like fantasy and adventure. This book would probably be best for kids aged eight to twelve.