Dead Island has been out for less than a week, but after playing if for a few hours you are guaranteed to have a few questions. Questions like, "How do the analog fighting controls work exactly?" or "Where the hell is that downed plane?"
If you're not into buying the strategy guide (available for $12.99 from Amazon.com) I would definitely check out the Dead Island Wiki Guide at IGN. It answered all the questions I had while playing, and even let me in on a few secrets that I hadn't thought of (like how to find the family that was featured in the awesome Dead Island trailer).
Dead Island Wiki Guide [IGN.com]