To add birds to your list(s), just choose the "Life List:..." option from the main menu in BirdsEye and then choose the "Edit" button in the upper right.
Be sure you have the appropriate region selected for the list you want to keep. For example, are you keeping just a World list,or do you want to track the birds you see in various regions. You can keep county, state, region, country, or just the world list. If you keep lists for a subregion you will see those birds automatically included in the higher level region. For example, a county list will also be included in the state, country and world lists. If you just keep a World list, the birds won't be reflected in any of the sub-regions.
On the BirdsEye home screen, you can see which list viewing you are currently in. Next to the checkbox symbol it will show Life List: Region (number). You can change the region by tapping the Life List -> Edit -> Set Region and selecting the area you want to view.