Today, the commercial product is farmed, processed, toasted, packaged, and sold in standard-size sheets about 18 cm by 21 cm (7 in by 8 in). Higher quality nori is thick, smooth, shiny, green, and has no holes. When stored for several months, nori sheets can change color to dark green-brownish.

The standard size of a whole nori sheet mentioned above influences the size of maki-mono. A full size sheet produces futomaki, and a half produces hosomaki and temaki. To produce gunkan and some other makimono, an appropriately sized piece of nori is cut from a whole sheet.

Nori by itself is an edible snack and is available with salt or flavored with teriyaki sauce. The flavored variety, however, tends to be of lesser quality and is not suitable for sushi.

When making fukusazushi, a paper-thin omelette may replace a sheet of nori as the wrapping. The omelette is traditionally made on a rectangular omelette pan (makiyakinabe), and used to form the pouch for the rice and fillings.

The content above is from wikipedia and used as an example post on this demonstration site.

True wasabi has anti-microbial properties and may reduce the risk of food poisoning. The traditional grating tool for wasabi is a sharkskin grater or samegawa oroshi. An imitation wasabi (seiyo-wasabi), made from horseradish and mustard powder and dyed green is common. It is found at lower-end kaiten zushi restaurants, in bento box sushi and at most restaurants outside of Japan. If manufactured in Japan, it may be labelled “Japanese Horseradish”.

Gari, sweet, pickled ginger is eaten with sushi to both cleanse the palate and aid in digestion. In Japan, green tea (ocha) is invariably served together with sushi. Better sushi restaurants often use a distinctive premium tea known as mecha. In sushi vocabulary, green tea is known as agari.

The content above is from wikipedia and used as an example post on this demonstration site.