Adjectives (Adjetivos)

Generally, you use these with ser. Unless they're only temporary, then you would use estar.
If a word has o/a at the end, that means it has two forms. Use the o for when you're talking about a guy or a masculine object. Use a when talking about a girl or a feminine object. To make these words plural, simply add an s. If there is only one form, it's used for both masculine and feminine.

generoso/a - generous
tacaño/a - stingy
paciente - patient
impaciente - impatient
deportista - athletic
artistico/a - artistic
atrevido/a - daring
prudente - cautious
ordenado/a - neat, tidy, organized
desordenado/a - messy, disorganized
trabajador/a - hardworking
perezoso/a - lazy
gracioso/a - funny
serio/a - serious
amable - nice, kind
callado/a - quiet
sociable - sociable (pronounced differently)
bajo/a - short
alto/a - tall
bonito/a - pretty
feo/a - ugly
grande - big
pequeño/a - small
gordo/a - heavy set
flaco/a - skinny
delgado/a - thin (in a nice way)
guapo/a - handsome, attractive
cariñoso/a - caring, affectionate
simpático/a - nice friendly, sympathetic
antipático/a - unpleasant, unsympathetic
atractivo/a - attractive
intelegente - intelligent
tonto/a - foolish
fantástico/a - fantastic

muy - very (put before the above adjectives)

Now, I'm sure you're wondering how to use these in actual sentences. Simply conjugate the verb, either ser or estar, and then add the adjective.

He is funny. - Él es gracioso.
I am quiet. - Estoy callada.
We are artistic. - Nosotros somos artisticos.
The table is messy today. - La mesa está desordenada hoy.