Quick answer
Ю ю = yu, the English word “you”. After a consonant it drops the y and softens the consonant instead: лю́бит is “lyúbit”.
yu
How to say it
At the start of a word or after a vowel: “you”. After a consonant: the oo of “boot”, with the consonant softened.
Ю in verb endings
The first-person singular of many verbs ends in -ю: чита́ю, зна́ю, говорю́, люблю́. So does the third-person plural of the second conjugation: говоря́т has я, but пью́т and даю́т have ю. It is one of the most frequent letters in the verb system.
The four soft vowels
Я, е, ё, ю all do the same double job: a y-sound at the start, and softening after a consonant. Ю is the pair of у: лук (onion) versus люк (hatch) is the same consonant, hard then soft.
Typical mistakes
Reading лю́бит as “lyoobit” with a full y
“lyúbit” — the л is soft, no separate y
After a consonant, ю softens rather than adding a glide.
меню́ → в меню́е
в меню́
меню́ is indeclinable.
Check yourself
Which word contains Ю?