57's suck for snare because their rejection is terrible. In other words, they get lots of hat and make it sound like trebly ****. If the snare is one of those incredibly loud ear exploding tight ones that is 5 times as loud as the rest of the kit, you dont have to worry so much about it, but thats rarely the case. A mic with a tighter pattern and better off axis response will serve you much better. If you use a 57, or any other mic for that matter, get it out over the snare as far as you can, with the hats in about the 120 degree area from the front. THe mic is going to pick up the most from the very front and the very rear. Kind of angle it to the side some. I have good luck with the Sennheisers. Much better mics with better properties all around. If you can afford a 441 (and your drummer wont hit it) the rejection is so awesome its not even funny. Barely gets any hats at all. The 57s will sound better if you boil out the transformer and bypass it though.
As far as micing hats, I've been doing something new lately thats been working great (when the drummers can handle it) I've been micing the hats and ride, and close micing everything else and also using a room mic pretty far back, and having them play without hitting cymbals. After we are done tracking, I re-mic the cymbals with either a pair of overheads, or if they only have 2 or 3, I put a mic on each one, and then have them listen through the songs and put cymbals everywhere they want them. This works well for the following reasons:
1) I can compress and eq the snot out of all teh drums wihout having cymbals in my toms and snare. If yo uare a fan of adding distortion to your snare, you'll learn really quick what happens when you have too much cymbal bleed.
2) I can mess with the cymbal effects and placement without having the drums in the cymbals
3) I can focus on getting a better cymbal sound wihout worrying about how the drums sound through the overheads.
4) Having a mic on the hats gives me more control and a much better click sound.
Also, you can take something like drumkit from hell superior, and trigger all the cymbals and have some bomb sounding cymbals instead of micing them. If you have a midi keyoard and that program, its really easy. Play the song, press the keys as needed.
On micing the hats... doing it towards the edge gives a really washed out bassy kind of sound. Eck. Try micing towards the bell of the hats, straight down and pretty close, and then angle it towards the center (but away from the snare)of the hats but still closer to the bell. Play and record for 30 seconds. Listen. Move it around. Do it again, and again, until it sounds good. Its hit or miss, take the time to place them all right and listen to them. Its a luzery you can afford if yo uare doing it yourself. Why skimp on placement?
Also, make sure the drummer doesnt have the hats too wide open when they are open. They should BARELY open just a little bit when they are wide open. Just enough to sizzle and sound good. Even a half inch is too much. They should barely open, or they'll record like ****.
Good luck!
Paul