The letter l is represented by the International Phonetic Alphabet symbol /l/. It is a voiced consonant and does not have voiceless counterpart.

You will find the /l/ sound in words such as:
learn /lɜrn/
surely /ˈʃʊrli/
all /ɔl/

/l/ is an alveolar sound. Since this is an alveolar sound, your tongue will touch the alveolar ridge (the area where your teeth meets your gums). Your tongue will be tense as it touches the alveolar ridge while the air comes out from the sides of the tongue.