Unfortunately, as some or most of you might already know, when it comes to books featuring a lake fly fishing focus there aren't too many choices available.
1985 a classic stillwater techniques book was released, The Gilly, A Fly Fishers Guide to British Columbia. Since its initial release, The Gilly has become a classic and what I consider is a must have for anyone wishing to learn more about fly fishing lakes.
Of the 21 individual chapters that make up The Gilly, 17 are dedicated to the nuances, tricks, techniques and tactics needed to be successful fly fishing lakes, not only B.C lakes but lakes across North America as well. These nuances, tricks, techniques and tactics that are as applicable today as they were when The Gilly was first released. Good friend, Brian Chan, authored all of the entomology sections found at the end of most chapters. A pattern listing is also included.
I can't recommend this book enough if you are wishing to add to your stillwater knowledge. Copies of The Gilly are, I admit, not easy to find. Selecting through the Amazon link along the right margin of this blog is still, arguably, your best choice.