There's an enormous amount of good literature on this topic. I imagine there are some useful websites, but as an olde-fashioned traditionalist I'll steer you in the direction of some books.
A good place to start would be Samuel Eliot Morison's two-volume set, The European Discovery of America (Vol. I: The Northern Voyages; Vol. II: The Southern Voyages). Both are brilliantly written, thorough, and illustrated with plenty of good maps and other illustrations. Columbus, Drake, and Megellan are covered in the second volume. (To put Magellan in a book about the discovery of America is a little bit of stretch, but people don't argue with Admiral Morison.)
If those books whet your appetite, get Morison's full-length biography of Columbus. In my humble opinion it's the best thing that great historian ever wrote.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.