Hungary is for many an unknown destination, but it has a lot to offer to the tourist. Both the active and the relaxed traveller can get their pick.
Hungary has a continental climate, which 'normally' means that from about half of April till half of October the weather is very nice. In summer even above 30°C.
The official valuta is the Hungarian Forint. You can easily withdraw money everywhere and pay with your card.
Hungary is still a cheap destination. You can take a holiday without constantly counting.
Hungary is a member of the Schengen zone. This means there is no border control anymore. It is sufficient to bring your identity card. Don't forget an ID for your children!
The offical language is Hungarian. In most cities you can get by with English or German.
Hungary uses CET (CEST in summer) time, as the rest of Western-Europe. Considering the eastern location the day will appear to be at least one hour ahead of Great-Britain time.
This is the same as in most of Western-Europe (220/230V), so you should be able to use all your devices without any problems.