+1 on McMaster-Carr. Their online catalog is the best and fastest educational on bolts and nuts that there is. Everything there is actually available and in stock, and the prices, while high, are consistent indicators of the commonality of each thing. They also have nice, clear, well-written explanations of many things.
Another superb resource is Carroll Smith’s book Engineer to Win, which, although written from the perspective of racing, is the best general text on engineering that I’ve found pikashow ppsspp emulator
