Not sure where you are located but if you are in the States, I would start by going to a Lowe’s or Home Depot or another building supply store that carries books and magazines. Because they are geared toward homeowner construction, they have some good construction books that also have details and they describe how-to-do-it yourself so you can create your own details from their descriptions. Some of the ones that I picked up include:
-The Complete Guide to Landscape Construction: 60 Step-by-Step Projects for Creating a Perfect Landscape (by Black & Decker)
-Garden Pools, Fountains & Waterfalls – Design Ideas, Installation, Upkeep (by Sunset Books)
-The Art of Pebble Mosaics – Crative designs and techniques for paths and patios (by Maggy Howarth)
-Building Great Sheds – Creative ideas for simple structures (by Danielle Truscott with Barry Hamel)
-Deck & Patio Upgrades (by Ortho Books)