If you jailbreak, it's best if you know what you're doing. You have to be willing to read. Go to the hacks subforum and start reading the threads (read multiple pages) and read the stickies.
If you don't do your research, you're going to be the millionth idiot to post how you lost your jailbreak because you updated to the latest iOS or reset your iphone. . . and you really need your jailbreak. Don't be one of those people.
Decide if you're willing to put in the time to learn. If not, don't jailbreak. Most iphone users don't jailbreak and they're content.