Thomas Willeford's Steampunk Gear, Gadgets and Gizmos is a guide to making your own toys and artifacts! I was drawn to it by the instructions for making a great set of brass goggles but rather found myself enjoying the silly random tidbits of steampunk maker theory.
No one likes to say, "there are the Steampunk rules that you must follow," but there is a tendency within Steampunk art and fashion toward what I like to call "cog on a stick." The best way to avoid the "cog on a stick" effect is for things to have at least the illusion of functionality. You are allowed to do anything you like, but the rest of us are also allowed to point and laugh at you.
Fairly easy to follow along with and kinda humorous, Willeford gives advice on how to source parts, tools and kit that you'll find useful for making objects. He also details some projects that'll get you started and give you plenty of launching off points for whatever you might like to build.