Rules of Fasting.

1626. Fasting means that a person must, in obedience to the commands of Allah, from the time of Adhan for Fajr prayers up to Maghrib, avoid things, which will be mentioned later, and they invalidate fast.

Intention of fasting
What Invalidates a fast
What is unrecommended (Makrooh) for a fasting person
When Qadha and Kaffarah (Expiation) is Obligatory