值得 (zhídé) means "to be worth" doing something, and is often placed before a verb or a verb phrase. Note that it is used to describe whether an action is worth it but cannot be used to state that something is worth a certain monetary value where 值 must be used alone.
值得 as an adverb
值得 + Verb/[Verb phrase]
Bājīn de sǎnwén hěn zhídé yíkàn.
Ba Jin's prose is worth reading.
Zhè jiàn xiǎoshì bú zhídé nǐ huā shí jiān.
This little thing isn't worth your time.
值得 as an adjective
值得 can also be used as an adjective – on its own, or following a verb phrase.
[Verb phrase] + 值得
Is it worth it? Yes.
It is worthwhile to attend a university.
It is worthwhile to learn Chinese
When expressing that something is not worth doing, one can say something is either 不值得 or 值不得.