The verb gustar is used to express desire in Spanish. We would equate it to "like" in English.
You conjugate it using different personal pronouns
Me gusta = I like Nos gusta = we like
Te gusta = you like Os gusta = You all like (Spain)
Le gusta = could refer to he/she/you (formal) like Les gusta = You all/They like
You can also use the verb gustar with other infinitive verbs to tell what people like to do, such as:
Me gusta andar en patineta = I like to ride my skateboard
Te gusta comer mucho = You like to eat a lot.
(A ella) le gusta beber limonada = She likes to drink lemonade. *Notice with le gusta, we usually specify who is the subject of the sentence.
(A él) le gusta jugar al fútbol = He likes to play soccer.
Nos gusta dormir mucho = We like to sleep a lot.
Os gusta tomar cerveza = you guys (Spain) like to drink beer
Les gusta plantar árboles = You all/They like to plant trees.
You can also use gustar to tell people you like them (more than a friend):
Me gustas = I like (like) you
¿Te gusto? = Do you like me?
The way I rationalize "gustar" in my head is to think of the me, te, le, nos, os, les as the person or thing that likes something. Then we either use gusta or gustan depending on whether or not the thing that we like is singular or plural.
Ex. Me gusta tu cabello = I like your hair.
¿Te gustan los conciertos? = Do you like concerts? (The "gustan" refers to the plurality of the concerts, and te refers to tú (you))