I will agree that IT has "traditionally" been a male domain, but that is changing (although somewhat slowly in some areas). You will be handicaping your ability to be successful if you walk onto the job obsessed about what your subordinates will think about you.
Upper management appears to have faith in your abilities. If any of your new subordinates does have an attitude about females, you need to use the one weapon in your arsenal that can't be refuted, and that is the successful use of your abilities. Once you can prove that you are just as capable (or more capable) than the males, attitudes tend to change (or at least get pushed aside for the time being).
As Oldefar mentioned, make sure you receive a clear set of goals from your boss. Then formulate a clear set of goals of your own to pass to your subordinates. This is not to say that you should jump in and start making changes on your first day on the job. One of the marks of a "good" manager (or leader) is to be ableto walk into a new situation and make a quick assessment before doing anything. How are the team dynamics working? Is this a "renegade" group, doing their own thing with no leadership? Since this is a new position, obviously upper management feltit was necessary. Try to find out why, either from your boss, or through your own observations. Make any changes because they NEED to be made to make (or keep) this group successful.
Concentrate on your responsibilities and the responsibilitiesof your group, not on any preconcieved notions your subordinates may have about you.
Good luck with your new job.