What are the etiquettes of visiting a mosque?

Mosques are sacred places. Abu Hurayra reported that the Messenger of Allah (peace be upon him) said: عَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ أَحَبُّ الْبِلَادِ إِلَى اللَّهِ مَسَاجِدُهَا وَأَبْغَضُ...