I got an egg but can't view it anywhere will it just hatch after I've walked a certain number of steps?
Open your list of Pokemon and swipe right to get to your list of eggs. You can hold up to 9 eggs that you collect form Pokestops, and once you hit the 9-egg limit you won't find anymore when you activate a stop. To hatch an egg you need to place it in an incubator; you'll have one incubator with unlimited uses, and the remainder of them you'll have to buy from the Pokemon store using in-game currency.
Then you just walk to hatch the egg you're incubating. The longer the distance for it to hatch, the better the pokemon can be when it hatches: 2km, 5km, or 10km.
During beta, there wasn't a vibration alert when an egg hatched, which was kind of a pain. Since you have to keep the app open, you have to look at your phone on a regular basis to see if an egg hatched, as it seemed to take priority over Pokemon appearances. There was a few times that I would be walking around outside for long periods without being vibe-alerted to nearby Pokemon, when in fact my phone was sitting at the "hatching" screen waiting for user tap to continue.
Even when walking around outside, your phone's time-out lock screen may take priority over the app; in which case you won't get any vibration alerts at all once your phone goes into sleep mode. If that's the case with your phone, then you'll have to set a long time-out period for your lock screen.
The battery-saver mode in your in-game settings will dim the screen when you have it away from your face (e.g., you're walking around outside while holding your phone in your free hand). Your lock screen time out can still activate though (mine was doing so last night, bothersome) but it does help to conserve battery power.