By default , mIRC flood settings are 300-30-10-0, and Enable Flood protection is off.
With all the troubles we have been dealing lately on IRC with bunch of script kiddies trying out their new war scripts, I would suggest to set flood protection ON by default , and also I would change "Ignore person for" from 0 to 60 secs at least.
I know many complete newby users will be grateful for this.