What it means
ほうがいい gives advice that an action is better or preferable. It commonly follows a verb in the past form to say that someone should do something, and it follows a verb in the nai-form to say that someone should not do something. The advice can sound fairly direct, so the situation and relationship between speakers matter.
Usage note
ほうがいい is normally used with a verb in the past form for positive advice and with a verb in the nai-form for negative advice. Do not confuse this pattern with simple comparison using ほうがいい, which can mean that one choice is better than another.
How to use it
毎日薬を飲んだほうがいいです。
You should take medicine every day.
その道は通らないほうがいいです。
You had better not take that road.
毎日薬を飲んだほうがいい。
You should take medicine every day.
その道は通らないほうがいい。
You had better not take that road.
Example sentences
明日の朝は早いので、今夜は早く寝たほうがいいです。
Since tomorrow morning is early, you should go to bed early tonight.
旅行の前に、薬をかばんに入れたほうがいいです。
Before the trip, you should put medicine in your bag.
図書館では、携帯電話の電源を切ったほうがいいです。
At the library, you should turn off your mobile phone.