[Radek]

The Artifact spells. If you want to bless or enchant your items, you must have somebody who knows BOTH the Artifact spells AND the Enchants/Blessings skill. Give such character the items you want blessed or enchanted and enter the Temple (blessings) or the Mages Guild (enchanting). Click the Bless/Enchant icon. Your skill level in Blessings or Enchants will determine how much blessings or enchants you can cast on a particular item.

Notes:
1. Let us stress again - the enchanter must know both the spells and the skill. For example, if you have a priest with Artifact of Spirit and Artifact of Vines, a mage with Artifact of Fire and Artifact of Stone, and an assassin with Artifact of Fiends and Artifact of Moon and if you want use all these artifacts for blessings and enchanting then all three characters must know the Blessings and the Enchants skills.
2. The effects of particular artifact spells are listed in the Best Tips thread - both for blessings and for enchanting.
3. The skill level in Blessings/Enchants determines how much blessings or enchants can be cast to a particular item. Let us note that many items are already enchanted. These "default" enchants COUNTS. Therefore, if the item is already three times enchanted (for example, the Sword of Hearts), then you will need Enchants 4 to add one enchanting. And so on.
4. Blessings and enchants STACK. For example, if you want three enchants and four blessings and if you begin with enchants then you will need Enchants 3 and Blessings 7. Let us note that the final result of "mixed" blessings and enchantings does not depend on the order of enchanting and blessing. You could begin with blessings and then add enchants. In this case, you woud need Blessings 4 and Enchants 7.
Similarly, different kinds of blessings and enchants stack as well. If you want to bless an item for toughness (Artifact of Vines) thrice and for added damage (Artifact of Fiends) 4 times then you will need Blessings 7.
5. It is possible to enchant or bless an item "by parts". In the example above (with a priest, a mage, and an assassin), the priest can bless a weapon for toughness twice and then give it to the assassin. Now, the assassin can bless the weapon for damage five times. The priest must have Blessings 2 (assuming the weapon does not contain any "default" enchantments) and the assassin must have Blessings 7. See note 4.
6. It is useless to teach a character an Artifact spell without planning the Enchants or Blessings skill for him. It is useless to teach the Enchants or Blessings skill a characters which cannot gain any artifact spell. The best candidate for the Blessings and Enchants skills is a universal spellcaster which knows all magic schools and which will be taught all artifact spells.