what is expected of me while I stay there
If someone carries your luggage to your room, they expect a tip ($1 to $2 per bag). It's also customary to leave a tip for the maid ($1 to $3 per day). Otherwise, it's really the other way round: it's the job of the hotel staff to meet your expectations (within reasonable bounds) - you're paying, after all.
what is provided for me and what I should bring
The hotel rating can give you some idea of what you can expect.
The hotel will provide towels, and you can get new ones every day (nowadays there's usually a sign that says to leave the towels on the floor if you want new ones). Bedsheets will be changed at least once per week, and the room cleaned daily.
They usually also provide small packages of things like toothpaste and shampoo, but not necessarily enough for a stay longer than a few days. There may be a clothes cleaning service, but you'll have to ask for it.
Many (but not all) hotels have hair driers in every bathroom. You should bring any other appliances you need. Nowadays, many hotels have some sort of internet connection in the rooms, but it may or may not be free.
If you have booked the room with breakfast included it will be served in a dining room in a fixed time frame (e.g. between 7AM and 10AM).
is there any gotcha that I should keep on the look out for?
There is a "check-in time" (typically late afternoon) - you probably cannot get into your room before that time when you arrive, as it may still be need to cleaned up after the previous guest. Correspondingly, on the day you leave you have to vacate the room and "check out" at the reception before a certain time (usually 10AM or 11AM) - if you don't, you may have to pay for an extra day. If you arrive before the check-in time or leave significantly after check-out time, most hotels offer to store your luggage for you while you spend the time somewhere else (at no extra cost).
Many hotels have a "minibar" in the rooms, which is a small fridge containing various beverages. These usually cost extra (prices are listed on the fridge door or a leaflet somewhere) and may be very expensive. But this seems to have gone out of fashion and I've seen a lot of empty minibars (which can be useful to keep your own stuff in).
The maid will come into your room every day to clean up - usually around noon. You can hang a sign on the door handle if you're in the room and don't want to be disturbed, and they'll come back some other time. Theoretically they could steal things from you; this is very rare, but many hotels have installed a small safe in every room to deposit exceptionally valuable items.