I've posted on beginnings before, but it was mostly about How Not to Begin Your Novel. Since then, I've found some helpful sources that tell what you should do.
One thing I love about Darcy Pattison is the way things are spelled out so precisely. (I like it when people explain everyday processes into tiny, easy-to-digest pieces.) 12 Ways to Open Your Novel is no different. Seriously, it doesn't get any simpler than this. Here are literally 12 opening lines/techniques that have been successful in the past, complete with examples.
How To Write Your Novel's First Chapter according to C. Patrick Shultz: POV, setting, a mystery, a fascinating character... these are all great ways to grab a reader. And you need to grab a reader quick.
James Scott Bell has a different approach to a similar task: to Grab Them On Page One, you need to start by stirring the pot. Start at the point where things change for the main character, with a disturbance.
Larry Brooks never ceases to impress. The Single Most Powerful Tool You'll Ever See that Fits on One Page is his fantastic list of must-haves for your story (which centers around how you begin, of course).
I hope these help you as much as they helped me.