I started building effects out of high school in 2002, its been a solid 7 years of building/designing. I set up a work bench at my parent's house and built a full pedal board with all home brew effects.
Clones I've built: Fuzz Face, TS-808, Dean Pitch Shifter (General Guitar Gadgets), EH pulsar, EH small stone, EH small clone, EH economy memory man, EH deluxe memory man, Ibanez AD-80, EH big muff, EH doctor Q, EH LPB, EH Frequency Analyzer, Boss slow gear, MXR phase 90, MXR D-comp, MXR dist +, Orange squeezer, Tremulus Lune, Pro Co Rat, MN3011 bucket reverb (and probably a few more I can't think of).
A lot of the clones I built were heavily moded to my own taste, soon I started doing my own designs. With the exception of the first two PCB's I ever did, I designed ALL of my layouts. They were always like little puzzles and I loved it.
I was gaining an immense knowledge base of audio schematics and electronics in general, but I started going to school in 2003 and recently graduated from the University of Maryland at College Park in December 08 with a B.S. in Electrical Engineering. I gained a lot of IC, Filter, DSP and general analog circuit design experience there. I'm now a full time engineer at a local telecom company and I build and test effects with the rest of my time at my shop in Laurel, MD.
I sell directly to Atomic Music, a guitar shop in Beltsville, MD. I sell at the shop the two effects I designed, the "Looker" optical tremolo and the "Super Time Warp" analog delay. I just started building larger batches of these pedals and can estimate the yearly quantities, both models combined to be about 40-50 pedals.