Want to Learn How to Eat Sushi in 10 Easy Steps?

1. Wipe your Hands. If you were provided with a Oshibori (rolled up wet hand towel) go ahead and wipe your hands off before starting on your meal. This is done because it is accepted and proper to eat most sushi with your fingers (not sashimi though, use chopsticks for that). Roll or fold your Oshibori and put it back in the dish it was delivered on after wiping your fingers.
2. Break apart your disposable Chopsticks. If you were given disposable chopsticks break them apart. If they are the cheap ones, you will probably notice some splinter looking pieces hanging off of it. Or maybe some rough edges. In this case, rub the eating ends of the chopsticks against each other to smooth the wood and remove the splinters. If they are the good kind of disposable chopsticks, they won't have splinters so don't rub them together; this will be an insult and you will be insinuating that their chopsticks are cheap. 
3. Mix wasabi in your soy sauce if you are so inclined. I will warn you that this is a highly debated topic and the "proper" thing to do here according to the "experts" is to NOT put wasabi in your soy sauce. I disagree, but read why here...and here... before you decide what to do. If you want more wasabi burn but still want to be "proper", then get a little wasabi on your chopstick and swipe it onto your sushi. Do be careful however, if you have never had wasabi before, as it will give you a slight heat burn, mainly felt in the nostrils (not burn your tongue peppery) that will go away quickly when you drink something. Try very little at first till you can gauge the amount of heat that you want. Now we are ready to discover  how to eat sushi.
4. Pickup your Sushi with your fingers or your chopsticks. Either is fine. But especially for Nigiri (the sushi with a small rectangle of rice with a topping on top) it is easier to eat with your fingers. If you are eating sashimi (meat only, no sushi rice), DO pick that up that with your chopsticks... NOT your fingers...
   
5. When eating Nigiri, pick it up so that the meat is on the bottom. Dip the corner of the meat lightly in the soy sauce (or soy sauce and wasabi if you are rebelling against the experts like me) and put the whole sushi in your mouth so that the meat touches your tongue first. This is so you get a taste of the delicate meat before the sushi rice. Try not to bite the sushi in half if possible, and if you do hold it in your hand until you swallow the first half and then immediately eat the second half. It is an insult to put half eaten sushi back on the sushi plate. 
6. For a Maki roll, pick it up with chopsticks or your fingers. Dip it lightly into the soy sauce and pop the whole thing in your mouth. 
7. When to eat your Ginger. Ginger is meant to be eaten AFTER you swallow your sushi as it is used to cleanse your pallet before you eat another piece of Sushi. This is similar to cleansing your pallet with a cracker between different types of wind. Again, here this is debatable. My Japanese mother always takes a bite of ginger WITH her sushi. And so do I and a lot of her japanese friends and relatives. I say this. Decide for yourself. If you want to stick strictly to so called hardcore sushi etiquette, then take a bite of ginger after swallowing your sushi and be done with it. If you are open, then try it with your sushi and see if you like it and eat it that way if you do. You will be in good company if you decide on the latter, as most Japanese I know do it this way too. 
8. Follow up with a sip of Green Tea, Beer, or whatever you are drinking. Again, this is like another pallet cleanser; preparing you for the next bite of sushi. Honestly, Green Tea is probably the best here as it leaves your mouth clean and refreshed. But I will admit, I will almost always have a sip of beer too. 
9. You can wipe your hands with your Oshibori after each piece of sushi but it is not necessary. This is your choice. 
10. When you are done, do wipe your hands with your oshibori one final time and place your chopsticks together and pointed to the left on the chopstick holder. 

And there you have it. How to eat Sushi in ten easy steps!