You want to record stereo. I don't use Garage Band but it probably records to an AIFF format. Make sure you clean the records with Alcohol solvent of some kind. Leave yourself some headroom. Peak around -3. If you don't and you get some clicks it won't be pretty.

I use AAC encoder for I tunes. It's the best comprimise. Ask your client first there is Apples "lossles codec" which will eat up more space. AAC works for most aps.

You will need to go through some sort of riaa pre amp before you go int the Mac (Alice phono pack)also your choice of cartridge and stylus is quite critical.

"Should I record into Garageband on a mono or stereo track?"

i think it's safe to say that stereo is here to stay..... most records recorded in the last 40 years is in stereo :shock:

Good lord, don't use alcohol if the record is in any way valuable.

Use lukewarm soapy water. (use the mildest soap you can find - Ivory snow used to be the soap of choice, if you can find it.)

GENTLY clean it in the direction of the grooves, pat-dry, and lay it on a soft towel (the less lint the better.)

Use a de-static matt if you have one, and don't touch the playing surface at all. (Thumb and middle finger to hold the disc).

Play it as little as possible, preferably all the way through in one pass, once you've set the levels. (Definitely use an RAIA preamp to get the right EQ for LP or 45 rpm discs). Declick and decrackle as needed with your software. Dont' go too far, but see what you can do with it.

You may also to EQ/roll off anything below 80 HZ or so (or even lower). All you'll get down there is AC hum and TT noise. Get rid of it and be done with it, it'll help you get the best levels as well.

Good luck with it. If you're trying to do any kind of audiophile restoration, you'll find out in a hurry why vinyl didn't stick around much past the mid 80's.