Grammar JLPT Level N4 - Lesson 24

Structure of し (Reasons):

Verb (A) + し + （Verb (B) + し）
［い］Adjective (A) + し + （［い］Adjective (B) + し）
［な］Adjective (A) + だ + し + （［な］Adjective (B) + だ + し）
Noun (A) + だ + し + （Noun (B) + だ + し）

Details about し (Reasons):

Like て, し is a conjunction particle. This means that it is used for linking the (A) and (B) parts of a sentence, and describing that link in some way. The 'description' that し will highlight is 'reasons'. Regularly it is translated simply as 'and'.
し may be connected to the end of almost any word, but will require a だ before it when it comes after nouns or な-Adjectives. し will follow every 'reason' that is being listed in a sentence. However, the last し may be replaced with から or ので, before the 'result' is stated.

彼女(かのじょ)はピアノが弾(ひ)けるし、スポーツができるし、彼女(かのじょ)に出来(でき)ないことはないと思(おも)う。
She can play the piano and she can do sports. I think there isn't anything she can't do.
このレストランは高(たか)いし、まずいし、何(なに)もいいところがない。
This restaurant is expensive and doesn't taste good. There are no good parts.
彼(かれ)は真面目(まじめ)だし、親切(しんせつ)だし、彼(かれ)と友達(ともだち)でよかった。
He is serious and nice. I am glad that he is my friend.
今日(きょう)は休(やす)みだし、晴(は)れだし、今日(きょう)は公園(こうえん)に行(い)こう。
Today is my day off, and it's sunny, so let's go to the park.

Using し will indicate that each 'reason' being listed is of equal weight/importance. Because of this, it would not be appropriate to use in sentences where one of the reasons clearly far outweighs everything else.

昨日(きのう)は雨(あめ)が降(ふ)ってたし、おばあちゃんも亡(な)くなったし、悲(かな)しいな。
It was raining yesterday and my grandmother also passed away, so I'm sad. (Unnatural Japanese, as the level of sadness between losing your grandmother, and it being a rainy day would be completely different)