1. The Torah specifies that all melachot (work) are forbidden on Yom Tob, except for such work which is related to the preparation of food for the Yom Tob (Exodus 12:16). (Whereas on Shabbat no form of work at all is allowed.)
This includes such actions as kneading, baking and cooking. These are permitted on Yom Tob because with freshly cooked food, the happiness of the holiday is enhanced. If a food would taste equally as good if prepared before Yom Tob, it should be done before.
2. Any form of work which is forbidden on Shabbat et is permitted on Yom Tob, is allowed only in connection with the preparation of food needed for that day only.
3. Food may not be prepared on the first day of Yom Tob for the second day.
4. One may not create a new flame on Yom Tob. Striking a match is prohibited. But one may make a new flame from an already existing flame - from a stove, a candle, or a lit pilot.
5. A flame that will be used for baking or cooking on Yom Tob should be lit before Yom Tob.