You must go to the Store, the shopping cart icon on the top bar of the game's menu after you log in.

From there, click on the tab at the bottom labeled Champions.

Find your champion, click on him/her/it to unlock, and then select whether or not you're paying with Influence Points, or with Riot Points.

Enjoy!

Ok, the first 10 like you called the Rotation (Free) Heroes. Every week (or so) the 10 free champions rotate. So you can give the heroes a try and see someone that fits your playstyle.

When you finish a game, you probably have noticed that you gain two things:

IP and EXP

EXP means you higher level, the cap is 30. More levels means more Runes Slots and more Masteries points.

IP Is the in game currency, you can buy Runes and Champions permanently.

In order to do that, you have to click in the shopping cart icon (left upper corner of the LoL client) and click in the champions tab. Next sort by IP. You'll see the champions that you can afford. I recomend that you give them a try in the free rotation week.

Besides, you can also buy RP (Riot Points) with real life money. RP can also be used to unlock champions but no runes. You can also buy IP/EXP boosts, to gain more of that.


Hope it helps,.

READ THIS

http://www.leagueoflegends.com/board...d.php?t=194210