Best way to jailbreak iPhone 5?

I want to play pokemon, and evidently to get something I need for it, called cydia, I need to jailbreak this phone.

I have 0 idea how to do this. I guess it's done with a program? I searched best ways to do it, and an article I found listed this one as the best:

JailbreakUnlock

http://jailbreakunlock.info/

That one costs 20 bucks, and I have no problem with paying the fee, but is it a good program to do it/trustworthy?

What concerns should I have with jailbreaking if any? (Aside from warranty problems)

Thanks guys

Added (1). I have 6.1.3, but there's currently and update I can do to go to 6.1.4, can I do it on this?

NO DON'T DO IT!
The ones that charge you are a scam. There are a bunch of free jailbreak tools. Unfortunately, if you have iOS 6.1.3 there's no jailbreak currently for the iPhone 5. If you have a previous iOS version, then you can use Evasi0n.

If you have 6.1.3, then you'll have to wait for iOS 7, because 6.1.3 is unjailbreakable.

RedSn0w or jailbreakme.com