goth
the personality
people who express their souls in a dark way. real goths don't cut themselves (some do, but it's not a goth trait... there are preppy cutters too.) real goths could be atheistic, christian, jewish, wiccan, agnostic, whatever... goths don't worship satan. goth music could range from classics like Evanescence and Linkin Park to Wicked and Rent or even Enya... i like to think of myself as the founder of the "broadway goth," goths that are theatrical and artistic. real goths are open to friendships with everyone and never exclude someone because they're not "goth" enough. goths also tend to have fire in their souls and dislike conforming to other people's set rules. this sometimes impacts their grades, which gives way to the rumors that goths are stupid and stubborn.
the style
hot topic is really a punk store, but it has goth things as well. however, you can get goth stuff lots more places... personally, my shopping consists mainly of thrift stores (i trade old clothes in for store credit), old navy (really simple things like, idk, swim suits, plain black tee shirts, zip up sweatshirts) and hot topic for odd items. a lot of goths don't wear solid black all the time because they have unique style and wear what they want. also, handmade clothing is very goth. 
rixa's advice to beginners
my advice to beginning goths everywhere is this- don't feel pressured into doing things because you're afraid not to be goth. you don't have to wear black lipstick and eyeshadow if you don't want to! you don't have to listen to screaming metal if you don't want to! if mom has issues with chains and multiple piercings, you don't have to! opt for a victorian look (think vampires and red roses) or maybe something cute and sweet (like cute graphic tees and converse). goth is what you make it. not what other people say. and never listen to people when they say you're a poser, because unless you follow what everyone else thinks is goth, you're not. 
there is also such a thing as gothic literature... a famous gothic writer is edgar allen poe. lemony snicket is not a gothic author. alice in wonderland is a gothic type book because the story is kind of dark humor and just a little strange.
my personal favorites
striped leggings and plaid skirt together 
lace fingerless gloves (i made mine)
corset top (got mine at forever 21, started modifying a black tank top last night)
black boots (mine are dress boots and i've had them for nearly 4 years) 
fun jewelry (my favorite piece is two random old fashioned keys i found that i put on a chain)
good old fashioned deformed cargo pants
low cut converse 
my favorite goth musician is amy lee of evanescence.