What are the do's and do not's of jailbreaking?

I'm looking to get an ipad in the next couple months for a few reasons. I already own an iphone which isn't jailbroken (I personally don't see the need for jailbreaking), but there is a specific app that is only available on japan itunes that I know has been cracked for jailbroken ipads. However, I don't mind paying for apps (but the pricing system in this particular app is through the roof; it'd cost upwards of $150 to get all the content, plus the hurdles of getting it from the japan app store). Are there specific things I need to avoid with a jailbroken device, or would I be pretty much free to shop the app store otherwise? Or would jailbreaking be an all or nothing endeavor in which I'd have to find cracked versions of everything I want in order to utilize them? I'd rather not deal with a huge headache, but if it's what I'd have to do, I'll have to go along with it.

Thanks!