Recently, eBird released a major update to the maps in their Explore Data section. Now called Range and Point Maps, these are now fullscreen, overlaid on Google Maps tiles with lots of extra features. At full world level zoom, occurrences are calculated in blocks of varying shades of purple. As you zoom in, you eventually get to a point where actual bird reports are displayed, each with a link to the checklist that bird was reported in. The new ability to view the checklists the species was reported in is a great feature, and should be a great tool in figuring out what birds to expect when visiting new areas.
They have also added the ability to view sightings by a date range, so you can check out breeding vs winter ranges for various species. Check out the screen shots below for a comparison of Cerulean Warbler breeding and wintering grounds.
You can also check out the distribution of different subspecies as shown below in the range maps for both eastern and western Willets.
There is a lot of information out there for you to discover so I would really recommend digging into this tool and using it whenever you have the chance.
The one thing I would like to see added to the options is the ability to show the last 10 days worth of sightings. It would also be handy to have a preference for the zoom level and location that you are most interested in.