Bouncing a file for mastering...

Export it in the original sample rate/Bit depth of the project without any Limiting/compressing on the Master outs. This is done by bouncing your song into a Stereo interleaved file (hit the Bounce button at the bottom of your Master Outs ->menue opens->set Locators according to your song length->go.) Leave enough headroom, you can add gain in the Mastering process.

PCM->aiff or .wav. All the others are compressed formats, no good for Mastering.

I would do this in Wave Burner if I was to master a CD in the "red book" CD standard (44.1 - 16 Bit). You can use all your Mastering plugs in there, and import as many tracks a CD can hold, crossfade them, set index points - whatever.
If I was just to master a single track I would do that in Logic as you suggested, use all my mastering plugs in there. If it´s film work I will leave it at 48 khz/24 Bit which is my usual project setting.

If you want to use Logic's Mastering presets, check the Channel strip settings in the output channel. I wouldn't advise that but it might give you idea what to look for. There actually is a template for mastering but I never used it.

There is a Mastering template when you boot up Logic- I haven't used it but it's there. You can also do it the way you have suggested, and you can also use Wave Burner I would imagine. Also there are popular programs like Bias Peak.

There is a book by Bob Katz ( http://books.google.com/books?id=EBCmpwGCROMC&dq=BobKatz&hl=en&prev=http://www.google.com/search?hl=en&rlz=&q=bob+katz&btnG=GoogleSearch&sa=X&oi=print&ct=result&cd=2&cad=author-navigational) that is a good read and very informative.\

When one masters, you take the final mix and apply careful final EQ and some compression, depending on the needs of a song, and make sure that all the levels are the same for the whole package (CD or whatever). Maybe you already know this, I'm just throwing it out there- and I don't know squat else except what I have told you, so I'm on my way now.

a question for you is why are you bouncing your project down to a stereo file before mastering. When you master you want each track on its own. Bounce each track individually if you want to move them to another session.

What? Man, you're confusing something here - he wants to master not mix his tracks.