A few easy steps to participate:
1. Register on Cornell's ornithology site.
2. For 15 minutes or more, count the birds that you see. Keep track of the kinds of birds you see and how long you watched.
3. Make your best estimate of how many birds you see of each species. For example, five Northern Cardinals, three American Crows. Huge flocks may be a challenge, but your best guess is still valuable. If you're not sure about species (who is?) they have a checklist that you can select for our local area with common birds. Click here to create your local checklist by entering your zip code or town.
4. Upload your list on the site, and you're done!
In 2013, people in 111 countries counted 33,464,616 birds on 137,998 checklists, documenting 4,258 species, which amounted to more than one-third of the world's bird species.
"People who care about birds can change the world," said Audubon chief scientist Gary Langham. "Technology has made it possible for people everywhere to unite around a shared love of birds and a commitment to protecting them." See their press release here.
The also have a cute participation certificate that you can print out for kids.