Most good dictionaries include the phonemic pronunciation of words, this is the way words sound when spoken in English. The phonemic pronunciation chart is explained here
When using a printed dictionary or an online dictionary such as Macmillan dictionary the word will have its phonemic pronunciation displayed using the phonemic symbols. It is good practice to use an online dictionary and listen to the sound of the word, speak the word, then listen again to see if your pronunciation is accurate.
Macmillan Publishers also produce a handy app to support pronunciation. There is a free version, for more information click here