There are two main ways of storing herbs that you have grown.
Drying. Pick your herbs in the morning before the sun is up. Wash and pat dry with a paper towel. Either spread onto a baking sheet and place into a a low oven 130C/260F gas mark one half. Alternatively , tie the herbs into small bunches and hang them up in a warm dry room. When they are dry, crush the herbs and place them into an airtight container.
Freezing. Pick your herbs first thing in the morning and rinse them off in your kitchen. While they are still wet, put them in a zipper seal bag with no air and place them in the freezer. After they are frozen you can take a rolling pin to them and crush them up fast, with no mess! Just take as much out of the bag as you want to use at any given time and refreeze the rest!
You can also comnine the two above methods: after cutting your herbs dry them in the oven at about 225 degree for about an hour. When your herbs are dried you can crumbled them into ice cube trays and then fill with water and freeze. After your cubes are frozen you can continue and freeze more herbs this way - storing the ice cubes in a bag marked with what the herb is. When your recipe calls for a certain herb just throw and ice cube in!