I can kind of relate to this since I bought my first bow only a month ago. I think what Mauser said is right on. I think you can be ready in a month if you put in a lot of practice. I've been shooting 70-100 arrows a day since I got my bow and I now feel comfortable that I could make an ethical shot if given the opportunity. You'll want to practice enough so that, especially with a new bow, you'll have time to work out any kinks or setup issues. I recently discovered some major problems with my setup and got them resolved. I'm glad I put in enough time practicing to reveal those problems and not have them appear at "crunch time." Mauser is also right that there are a lot of guys out there that don't put in the time that they should. I was at a range yesterday with some guys who said they don't pull their bows out until a few weeks before season and they're shooting showed it. They never made a solid hit on target, but rationalized it with the familiar "well...it's a dead deer" mantra.

Anyway, yes I think you can get ready fairly quickly. Just put in the time and make your practice count. I would also say, don't judge your readiness by your best shot, but by your worst. And, when hunting, stick to a range at which you know you can perform.