English is not as widely spoken in Japan as in many other Asian countries. In the major cities such as Tokyo and Kyoto there are more English speakers and in most situations you will usually find someone around who speaks English.
However, the further away from large urban areas you get, the less English you will find spoken - and in rural areas you may struggle to find anyone who understands you! There are often staff who speak some English at tourist sights and attractions. English (to differing degrees!) is spoken at most of the accommodation options we work with.
Signs in English follow a similar pattern - plenty in the big cities, rather less in smaller towns and rural areas. All but the tiniest train stations are signposted in English, including the whole rail and subway network in Tokyo.
English explanations at sights and attractions vary; some have plenty of information in English, some have rather less. Menus in English can be found at some restaurants, again mainly those in the big cities with more regular non-Japanese trade. However, many restaurants that do not have English menus will have picture menus which take a lot of the stress and worry out of ordering!