There are essentially two types of flushing; flushing your pot and flushing your plant. Flushing your pot means you run an amount of pH adjusted water equal to 2-3 times the volume of your pot, through your pot. Some people flush their pots at regular intervals as a maintenance measure. Other times, when your plant is having problems such as nute lock out, a flush is mandated to clean salts and stuff out of your pot.

The second kind of flushing, flushing your plant, is a process that is done at the end of your grow to allow the plant to use up all of the stored nutrients in its sytem, which leads to much better tasting bud. The final flush can last for up to two weeks (different people flush for different lengths of time - for different reasons). During the final flush, the plants are fed only water (there are some addatives that can be used during the final flush, but that's outside the scope of this answer). Due to the no-nute diet, the plants use up all of the chemicals left in the plant's system. This cleans the plant and removes not only the chemicals but also their harsh taste.

Skrappie mentioned the reason for curing. The process itself entails putting newly dried bud into mason jars and storing them there for a couple of weeks. Real connissuers might cure for several months, as the smoking quality of the bud increases with longer curing. During the curing process, the jars are opened once or more per day to allow moisture to escape the jar, then resealed to allow the buds to evenly distribute the remaining moisture.

PC :smokin: