The fundamental tools for bird-watching are your eyes and ears.
Birds can be readily identified by both sight and sound.
There are accomplished bird-watchers who are visually impaired and accomplished bird-watchers who are unable to hear the birds at all.
Although one can observe a great deal without binoculars, seeing the kind of detail necessary for identifying birds and observing the details of their behavior requires the aid of binoculars.
Usable binoculars for bird-watching range in price from $50 up to $3000. These two articles at Audubon.org are excellent. They cover critical details and review binoculars in all price ranges:
Audubon Online Guide to Binoculars
How to Choose Binoculars
A few suggestions:
The two articles mentioned above will provide guidance on all of these issues.
A field guide provides pictures, range maps, habitat details, migration information, diet information, identification aids and sound descriptions for every species in an area.
Field Guides are available in Print, Online and Phone App formats.
Very Important: Online Field Guides (as well as phone-based guides) provide extensive recordings of the Songs and Calls of every North American Species. See the "eBird" and "Other Online Resources" section for information on freely available sources.
Print Field Guides are generally the most complete and offer the advantage of being able to easily compare species within and between families.
Print Field Guides cover all the birds in a specific region. In our area, most bird-watchers have at least one guide to all of North America and sometimes another (often small enough to carry in the field) covering just the species seen is the western part of the country.
Widely used guides in the USA include:
Online Field Guides: Here are links to two free guides:
All About Birds from The Cornell Lab of Ornithology, is perhaps the most extensive guide on the web.
Audubon.org provides this comprehensive guide: Audubon Guide to North American Birds.
In addition to the standard Field Guide components, these offer extensive field recordings of all species!
Phone App Field Guides offer a compact way to carry a large amount of information into the field.
Availability varies by phone, but the Audubon and the Sibley Apps are widely used.
A field notebook (as simple as a 3"x5" notepad) can provide a convenient way of recording sightings as well as making notes about visual, behavioral or aural details.
Some birders use their smart phones for some of these purposes. Many birders are now using the eBird Phone App to enter their observations in the field.
Most experienced birders would not say this is an essential tool. It may not be. But it is something new and as smart phones have found their way into most peoples' lives, one might view a Bird ID App as something not much different than a smart phone camera or a weather app or a compass app.
While the app will not substitute completely for your learned skills, it can certainly serve as a very useful learning aid. More detailed information about Merlin will be provided in the eBird section.
The learning value of going birding with more experienced birders cannot be overstated!
If you are out and see other birders, ask what they are seeing. Bird-watchers generally like to share information and can often help you to make sense out of a confounding identification.
A spotting scope can provide a level of detail of a distant bird unequaled by binoculars.
As you do more birding, you will eventually have the opportunity to observe a bird, perhaps a distant raptor or duck, through someone's scope.
Once you have some experience with scopes, you will be in a better position to decide if a scope is something that you might want to own.
A smart phone camera can sometimes make a useful photo, but an advanced point and shoot camera will provide a strong tool for identification and documentation.
Many birders now carry some form of a Point-and-Shoot camera. Advanced models with a physical zoom lens are particularly popular and can make excellent photos under the right conditions. They are generally fairly small and light. Something easy to carry around.
Beyond the Point-and-Shoot level is a whole realm of Bird Photography. Great lenses can help a photographer capture great photos. Bird Photography is a passion for many birders. You will find extensive information on the internet if this is something you are interested in.
Searching the internet will provide plenty of information about using whatever camera you have or think you might like to have. There are many video tutorials covering the entire topic of bird photography!
Recording the songs and other sounds of bird is another whole realm.
If you are carrying a smart phone, then you have the capability of making very useful recordings. Here are websites at the Cornell Lab of Ornithology and at Audubon that cover smart phone recording:
The world leader in recording bird sounds is the Cornell Lab's "Center for Conservation Bioacoutics". They provide expertise and training at every level. Their offerings include free but powerful sound analysis software that can be downloaded from their site: Raven Lite