Korean can't use a bare dictionary form as a noun, so add -는 것 to the verb stem to mean "the doing of it." Then case-mark it like any noun: 것을 when it's the object (of 좋아해요, 싫어해요, etc.), 것이 when it's the subject. In speech these contract to two different forms - 것을 → 걸 (object) and 것이 → 게 (subject) - so they are never interchangeable.
Examples
- 저는 음악 듣는 것을 좋아해요.
- I like listening to music.
- 요리하는 걸 별로 안 좋아해요.
- I don't much like cooking.
- 책 읽는 게 제 취미예요.
- Reading books is my hobby.
- 한국어 배우는 게 재미있어요.
- Learning Korean is fun.
The mistake to avoid
Saying 읽는 게 좋아해요 - 게 is 것이 (subject), so it can't be the object of 좋아해요; use 읽는 걸 (= 것을) there.
Where this fits in
좋아하는 것, Korean A2: Talk about hobbies, likes and dislikes, and free-time plans.