Field guides are available to suit the needs of all. Small pocket sized field guides provide a quick reference to bird species. Larger field guides supply more indepth details on the birds.
Field guides are most often area specific, that is, they will only list birds within a certain geographical location (e.g. Country, state/province etc.).
Field guides may also only contain certain types of birds such as field guides for birds of prey or for garden birds. Each field guide differs slightly, however in general the order of the types of birds will be the same. Keep your field guide on hand just in case you spot an interesting bird!