Madrid Metro is fast, clean and safe (just beware of pickpockets when it's crowded).

An official interactive Metro map and trip planner in English is available online, here.

A good alternative is to use Google Maps. Not only are all bus stations and metro stops pinpointed, but also Madrid's Travel Consortium "sends" real time information about bus positions - and if you click on a bus stop, it will tell you exactly which buses stop there and the anticipated wait time for each one of them in that precise moment. Also, the "getting there" option of Google Maps offers a "public transport" alternative that suggests the best way of going by bus/metro from a given spot in Madrid to any other and the estimated trip time - and it works flawlessly.