Binoculars
Sometimes I go birding without my binoculars just to force myself to observe more closely, but it is rare. Binoculars change your whole view of the environment. Instead of wondering why some bird keeps flying out 10 feet from its perch on a fence and returning to the same spot, with binoculars, one sees the bird catch the insect. Instead of some bird just being "another little brown bird", the beautiful detailed head pattern of the Lark Sparrow (Chondestes grammacus)can be seen.
If you already have binoculars, they will work to get started. Don't rush out and buy a new pair. Get to know the ones you have. Take them into the field and start observing.
Usable binoculars range in price from $30 to more than $2000. Some birders will disagree with the $30 "usable" claim, but I make it anyway. Obviously, you get what you pay for and the $30 pair may not last a lifetime, but it is optically good enough to keep a novice birder going for at least a few years.
Deciding what binoculars to buy is not a simple task. There are many issues to consider. The best thing for a novice to do is to go birding with other birders and try out various binoculars. There are useful websites to consult and sales people at various mail order businesses can be very helpful.
Eye Relief
I put this topic in bold print because it is a critical consideration if you wear eyeglasses for distance viewing. If you are an eyeglass wearer, this one binocular specification may have more effect on your experience using binoculars than any other single thing.
Essentially, eye relief tells you how close you have to get the pupil of your eye to the lens of the binocular in order to see the full view. If your glasses rest 15mm from your eyes and the eye relief of the binoculars is 5mm, you are going to have a very limited and unsatisfactory view through your glasses. In the fast action world of birding, taking off your glasses is just not a possibility.
WARNING! At many binocular stores, the people selling the binoculars may have no knowledge of eye relief. I once read an article in a reputable birding magazine entitled "buy your dream binoculars" in which eye relief was not even mentioned. [Must have been written by someone who didn't wear glasses!]
So, if you have binoculars, use them. If you don't have them, spend some time educating yourself before you plunk down your money. Again, go birding with more experienced birders. They can help you with this matter. I always have extra binoculars with me for people to use if needed.
One of the most useful features are range maps. These tell you approximately where you can find a given species at any time of the year. Here's how it works. Let's say you see a Hummingbird in Velarde in early June. You go to the illustrations and see that there are more than fifteen hummingbirds to consider. That's a little intimidating. But now, you go to the range maps and find that there are only two hummingbird species that are likely to be in Velarde at that time. Identifying that Hummingbird has just become a much simpler task.
The following link takes you to a website about field guides:
http://www.birdwatching.com/bookstore/books_fieldguidesbasic.html