Does she work here? Use does with he, she, it, or one person or thing; use do with I, you, we, they, or plural subjects. The main verb stays in base form after either one.
Do you usually walk to work?
Does your brother play football on weekends? One person, so does.
We don't watch much TV these days.
He doesn't like coffee. The verb stays as like, not likes, after doesn't.
Do the kids need rides tomorrow? Plural subject, so do, not does.
Does this bus stop at the station? This bus is a single thing, so it takes does.
The double -s mistake
The most frequent slip is putting the -s on both verbs: Does she likes pizza? The -s already marks the third person, so it goes on does only, and the main verb returns to base form: Does she like pizza? The same applies to negatives, so He doesn't works here should be He doesn't work here.