The easiest and simplest way to get visa to Vietnam is to apply online for visa on arrival. What you need to do is just to sit in front of the computer/laptop for a while to fill out the application form, make payment, and wait only 1 or 2 working days, or even some hours to receive the visa approval letter via email. By showing this letter + passport + photos & paying the stamping fee to the Immigration upon arrival in Vietnam, you will get your visa stamped onto passport, and free to enter Vietnam.