I'd look at the guide posted, but hammies can be great pets, I certainly treasured mine. I did have the pet-shop bad sexing issue when I had mine, though even as a like 7 year old kid I never really trusted the pet's store sexing, though it took a while to convince my folks otherwise. However, eventually it gets to be pretty dang obvious a little boy hammy is a boy hammy.... (and thus Jewel became Julius lol)
I personally used one of those store cages which you could extend with various add-ons to make a fancy cage. They can climb pretty well so you can have upright parts, however I personally kept mine single story since my hammy was a silly little thing and sleep-walked. He'd fall asleep in an upper area and then you'd hear a "thud" and find a confused little hammy in a heap at the bottom of a tube. Needless to say the cage turned single story pretty quick (he's also sometimes sleep-walk while being held, so you'd have to gently keep him from falling off things).
Make sure you have a wheel, it will be used- as such go for one as quiet as possible if it will be housed near where you sleep. They run miles a night.
I've only ever had one hamster, but mine's personality stayed very similar to what it was like at the store/wherever you get it, and other's who've i've know have had similar experiences. Luckily mine was the sweetest little guy ever so I'm not complaining, but thats something to keep in mind, though I'm not sure how much a more unpleasant continued nature was the result of improper taming attempts or lack there of completely.
The only thing I didn't like about hammies is just how short their lifespan is. 2-3 years for the larger syrians (I had a long haired one), and 1-2 for the dwarves. They're with you for such a short time...