Anything at or above 192kbps MP3 is fine.
Below 192kbps it's fairly easy to hear sonic degradation on anything other than speech only/ simple recordings.
FLAC now seems to gradually be taking over from MP3 as the preferred file medium of storage but I can't say I hear any improvements with it.
I'll only use FLAC to rip the rarest or most important of recordings.
Giving each disc a quick cleaning wipe before ripping won't hurt either. I usually breathe on the disc first and then wipe it off using a clean cotton T shirt.
Some say that you should use 8x or 10x ripping speed and switch off error correction, but I can't say I've noticed any difference here either.
Therefore I tend to leave error correction on.