great advise so far....
i definitely wouldn't go over 25yds at the most...especially being new to bowhunting.
you need to practice as much as possible...daily if you have the time....even if you sling 10 arrows it's better than not at all.
like it was mentioned make sure you're fully concealed...camo everything...turkeys can see a knat land on a skeeters butt...lol....if you're gonna get a pop up make sure you practice shooting from it...trust me on that one...lol.
newbies should stay away from mouth calls (unless you're gifted from the start)...stick with a box call...or try the freak by primos...it's a good sounding first call and since it attaches to your leg there's less movement....make sure you don't call too much...probably the #1 mistake hunters make...also don't bring your calls in while scoutin'...you'll be tempted but it could totally backfire on you and blow it for the season.
and makesure you don't wear red,white, or blue...especially while huntin' on public land and during turkey season....things could get real ugly real fast.
and to re-enforce what coyotestalker said: HAVE PATIENCE!!! you'll never succeed in turkey huntin' if you don't.
best of luck to you and make sure you go to the bow forum as well...there's a lot of good advice for newbies there.