Attributes
Personality Traits define the basic manner in which your character behaves. Periodically, you will have to roll against a Personality Trait to see what you do in a given situation. Meet an attractive young maid at the feast? You can roll against Chaste to see if you resist her charms or against Lustful to try to hook up. Rolling under your score is a success. Rolling your score exactly is a critical. Rolling above your score is a failure. Rolling 20 (unless your score is 20+) is a fumble. If your score in something is above 20, you cannot fail and you add +1 to the die for each value above 20. So a 25 gives you a plus 5 and 15 or better is a critical.
When you use a Personality Trait as part of the story, the GM may announce that you have gotten a "check" in that trait. Put an "X" in place of the "_" next to that trait on your character sheet. During the Winter Phase, you will roll against your checked traits to see if any of them increase. In this manner, your Personality Traits will tend toward the way you play your character. Always drinking too much at the feasts? Your Indulgent will tend to rise.
Passions are things and people your character feels strongly about. In certain circumstances you can roll against your passions to determine your attitude or actions. In addition, in certain circumstances you can invoke a passion. Doing so can have dramatic effects. Defending you Lady Fair's honor in a duel against another knight? You can invoke you Amor or Love for her and if successful you will earn pluses for the combat. If you fail, you will earn minuses and could lose points in your Amor/Love. It is generally unwise to invoke Passions that are not at least 15.
Statistics are the basic measurements of your character, how large (SIZ), how quick (DEX), how powerful (STR), how much endurance (CON), and how attractive (APP). Other than SIZ, you can raise them using advancement points at the end of each year. They affect how much damage you deal, how fast you heal, how fast you move, and how much damage you can take.
Skills are a measurement of your facility in various disciplines. Skills can be grouped to some extent into Knightly skills (Combat skills, Heraldry, and Tourney), Social skills (Falconry, Gaming, Orate, and Hunting), Romance skills (Compose, Dancing, Flirting, Play, and Romance), Courtly skills (Courtesy, Heraldry, Intrigue, and Recognize), Survival skills (Awareness, Boating, Chirurgery, First Aid, and Swimming), and Knowledges (Faerie Lore, Folk Lore, Industry, Read, Religion, and Stewardship).
Knightly skills are important for gaining Glory as they are commonly used on quests and in tournaments. Social skills are useful for impressing other knights. Survival skills can make a real difference during adventures. Knowledges, especially Stewardship, can help your character figure things out.
In the early period of Arthur's reign, Romance skills are useful for getting a woman's attention but are unlikely by themselves to lead to marriage as a Father's (or other man's) approval is almost always necessary. Glory and Wealth are what make an attractive suitor.