I've read many a thread on the webz about how people are pissed because after contracting vampirism they are being attacked on sight, and therefore cannot feed on people. First, know that to feed you must pickpocket someone while sleeping. It will then give you the option to pickpocket or feed. Second, know that if you don't feed within a given time frame (I don't know it) you will go full vampire (never go full vampire). It can be a pain in the ass to have to travel to town and feed all the time, but I discovered the following on accident and it has made my vampire experience so much more awesome. First you have to acquire a companion. I like to call them my fang-bangers/familiars. Next you need to command your companion to sleep in a bed (any bed). Then you get real close and when they lay their head on the pillow you press action button on them. There's an extremely small window of opportunity before they get up so you'll have to be quick about it, and it might require a bit of practice. You will get all the benefits of feeding with half the work! You've now got a blood bank and someone to help you fight off baddies on those rare occasions when you have to venture out in the day.