When a power blesses your check, it adds 1 additional die of the type determined by the skill you're using. If it blesses your check twice, it adds 2 dice, and so on. So if you're using your Strength of d10, and you're blessed twice, you'll roll 3d10.
If your check doesn't use a skill because a power specifies the type of die to use, blessing the check adds another die of that type.
If a power blesses by a deity, or if a card used to bless has the Deity trait, add the deity's name as a trait to the check. For example, if a check is "blessed by Sarenrae” or is blessed by a card that has the trait "Deity: Sarenrae," add the Sarenrae trait to the check.
Any card that refers to a blessing of a particular deity applies to any blessing that has that deity's name as a trait.