It's stickied at the top of the board.
WANT A KANJI TATTOO? Read before you ask | Japan Forum
Japanese is classically written top to bottom, right to left.
If you want to ask about the appropriate translations, then feel free, but do be warned that not everyone is thrilled about people getting tattoos written in languages they don't understand (and likely can't even read aloud). Be sure to get a second (third...fourth...fifth...etc) opinion on anything that someone tells you; if you do get a tattoo, you'd probably rather it not say that you're an uninformed idiot.
Also realize that by choosing Japanese rather than Chinese, you may have to deal with having kana included which is something that some vehemently refuse to use (for some weird reason); sometimes you get lucky and words/phrases don't require them, but often you don't.