In general tattoos will heal in about a week with normal good care - sooner if your artist uses latest healing tape technology. It's not a big deal.
As for the "sensation" -- I prefer to describe it as annoying, more than painful. Yeah, it hurts, but it's not so bad that you ask the tattoo-er to stop but you're sure as hell looking forward to when it's all over. And like the healing tape - tattoo "guns" are way smoother and quieter and less pain-giving today than even a year ago.
Placement of the tattoo - the body part that's gonna get the ink - does vary the amount of discomfort (in my experience, for sure). I've got a flamey pattern on my tummy (looks like my crotch is on fire!) and the farther down Michelle (the artist) went, the more it hurt. Everybody will have his own experience to tell you, but what the fuck, go ahead and get some ink and find out how you tolerate it. The QoS won't be any easier or worse for healing or even the inking, so don't worry about that.Okay? Enjoy!