Thinking about starting to collect, need some help

So after getting into comics just about a year ago, I've really grown to love two characters in particular; Moon Knight and Daredevil.  I've only been reading their current runs, but am really into the idea of going back and getting their past stuff but I really don't know where to start and how to go about it.  So I ask, whats the best way to tackle this, and how big of a hunt/commitment is collecting full runs of characters?  

Sorry, but there are too many of these threads.  That's why we have one now:  The Where Should I Start thread