Is there a limit on how many questions I can ask?
How many posts can you ask on Stack Overflow itself? I see a limit for 50 questions per month; does this hold for all members?
The number of questions you can ask is outlined in Is there a limit on how many questions I can ask?
There is no (current) limit to the number of answers or comments you can make in a month.
Note: The limits are fairly new so you can expect to see users with greater than 50 questions in a 30 day period, or greater than 5 questions in 24 hours historically. Also, it might look to you as if someone has posted more than 6 questions in 24 hours, however bear in mind that stackoverflow runs on UTC, so the 24 hour period doesn't mesh with midnight-midnight in your timezone, even less so if the site uses a rolling 24 hour period.