This blog is dedicated to the idea that learning and playing guitar should be as fun as possible. It is a fine read if you are starting to learn guitar from scratch and if you tend to search for ways to be more creative.
Learn guitar and have fun too.
Guitarists usually don't have a choice as to whether or not their fretting hand has long fingernails. The reasons why is because it's easier to hit the exact string they want to hit; Having long fingernails on the fretting hand means that there is more chance of muting the string below. However, the plucking hand has more choice. Predictably, there is a lot of varying opinions on the merits of long fingernails on the plucking hand, but not within genres or styles of guitar. This blog post will be stating what is very common for guitarists across genres to do with their plucking hand.
Classical guitar is pretty uniform: Pretty much all classical guitarists these days play classical guitar with long fingernails on the plucking hand. For right-handed guitarists, this would be the right hand. vice versa for left-handed guitarists. It is rumored however that Fernando Sor, one of the great classical period composers for guitar, regretted his decision to remain without fingernails on his plucking hand. Everyone from Andres Segovia onward in history has had long fingernails.
Jazz guitarists are a different bunch. I have known plenty of jazz guitarists who have long fingernails and keep up with classical guitar. Long fingernails also come in handly for solo jazz guitar arrangements. Of course, there are jazz guitarists who just don't bother, and it's just the same. Sometimes the difference in tone is just a matter of personal preference.
The line gets divided a little bit more when it comes to fingerpicking. There is a dedicated number of fingerpicking guitarists who have long fingernails. They like the sound (I do too), and they are serious about tone. However, there are people without fingernails on the plucking hand in fingerpicking. Paul McCartney's famous song "Blackbird" was played without fingernails. It is merely one's personal preference.
After classical, jazz, and fingerpicking, it gets way less predictable. Rockers tend to just follow whatever works best for them. I have a feeling that a lot of rockers out there fear being called a sissy if they had long fingernails. However, Lindsey Buckingham of Fleetwood Mac has long fingernails and doesn't use a pick. Thom Yorke of Radio uses a pick primarily, and it's doubtful that he uses fingernails for his guitar playing. It's again just a matter of preference.
So should you? If you like being articulate with tone and like focusing on how a string sounds, then give it a shot. If not, then don't worry about it.