Æ or æ (the letter 'ash'?)

Can someone give me a more in depth explanation of the letter 'æ'. Is there more than one way to pronounce it? I know it is pronounced as a long 'ee' such as in near or nær but is there another way to pronounce it? And the name of the letter is Ash. Is the name supposed to be pronounced in an american way like the word ashes for example? Also I have been learning norwegian language for about 2 or 3 months now through song lyrics and just learned the word 'Far' for 'Father' with the r pronounced as a d sound. Why have I never seen this pronunciation in any other norwegian word contains an r?