Learn Russian: Это известный поэт.

When это is used to mean "This is" or "It is" to introduce someone or something, it acts as a fixed pointing word. It stays in its default neuter form regardless of the gender of the noun that follows.

Where is the word for "is" in this sentence?

Russian skips the verb "to be" in the present tense. Instead of saying "This is a famous poet", you simply put the words together: "This [a] famous poet".

Is the letter т in известный pronounced?

No, the т is silent here. When Russian has the consonant cluster -стн-, the т is usually dropped in speech to make the word easier to say. It sounds more like "iz-ves-nyy".

Why does известный end in -ый?

The ending -ый shows that this is a masculine adjective. Adjectives must match the gender of the noun they describe. Since поэт (poet) is a masculine noun, the adjective takes the masculine ending.