Definitely do so! I've been playing this game since closed beta now and it's really a lot of fun. If you played DotA then you'll love it, even if you dont know what DotA is odds are you'll love it even more. Instead of writing out why you should play and how much fun it is, it'd be much easier if you just downloaded it and played a game. The client isn't very large and the minimum system specs aren't very demanding either. So check it out and if you need somebody to help you learn the game better add me in game, my name is Jadilus. Also please use this link to sign up: https://signup.leagueoflegends.com?ref=4ba7cb22df7f5
If you end up liking the game and continue to play (which I'm confident you will) then I get goodies if you sign up from that link. I realize that makes absolutely no difference to you but when you start getting into the game you can do the same thing!