To Ring
intransitive verb, godan verb
This is a lot like 鳴く, which means "to chirp" (or some other animal noise). This has to do with noises too, but not so much animal and more like bells (including telephones). This word means to ring. If it helps, think of the る as a hint, kind of like the first sound of the word "ring" (る). So, る = "ring" and it's a verb, so to ring.
The reading can come from 鳴く. So long as you know the reading for that word you can know the reading for this word as well.
電話が鳴る
the telephone rings
音が鳴る
a sound is emitted
アラームが鳴る
the alarm goes off
お腹が鳴ってしまった。
My stomach growled.
電話が鳴っている。
The phone is ringing.
ドアのベルが鳴った。
The door bell rang.