Puggo - Jar Jar's Yoda said:
"Star Wars" is such a true classic, it's ranked by the AFI as the 13th best motion picture of all time. Watching the prequels first is like watching Casablanca, but first watching a parody of the movie that gives away everything that is going to happen in the original, sapping a lot of the drama from it. It's the same reason that people who record a football game don't want to know the final score before they go home to watch it.
It's pretty irrelevent when and if you see the prequels - as long as you don't see them before Star Wars and Empire Strikes Back.
Actually, watching the prequels first would be like watching a parody of Casablanca that tells you Rick and Ilsa had already met in America, then he knew she was married to Lazlo, with Jar Jar Binks inexplicably stealing 20 minutes of screen time as well. And then they tell you it's canon(!) for the real film.
Please, don't watch the prequels. RLM's reviews are all that is needed.