After you reach level ten you will gain access to the talent grids. There are three talent grids in total, and each one is full of both active spells as well as passive abilities. They can be accessed in the lower tabs of your Talents window.
At level ten you will start gaining a ruby voucher each time you level. The ruby vouchers will appear in the Currency tab of your Character Info window which can be accessed by pressing "K". Rubies can then be bought with the ruby voucher in addition to gold.
Rubies can also be earned by completing World Mysteries. World Mysteries are a series of quests that reveal a large amount of the lore of the game. There are a good number of rubies available exclusively from World Mysteries, so you should complete every single World Mystery quest you find.
The spells and abilities in the talent grids can be then learned by spending rubies to unlock the squares they are in. The first rank of a spell or ability can be learned by spending one ruby to unlock one of the squares it is in. In order to learn the second rank, you must then spend a ruby to unlock a different square that contains the same spell or ability. This means that there are many different ways that the various ranks of a spell or ability can be learned.
Not all of the spells or abilities in the talent grid will be immediately available. You may only access the spells or abilities that are located in the squares that are next to spells or abilities that have already been learned. This adds an extra level of complexity that must be considered when you spend your rubies. However, it also allows for a greater amount of flexibility for you can take different paths to learn the same spell or ability.