For the most part being in the military as a female is a good go. Personally, I've had issues along the way with some males not giving me the time of day simply because I am female...but that happens in any occupation dominated by men for so many years, and shouldn't be that way, but can only be expected. My advice to you is to do your best, don't go through with a chip on your shoulder, you can only do your best, and strive to achieve the level of ability that anyone else should expect to have.
Mo-litia is right in saying that you should work to achieve the same standard as men, although you should do that no matter what your trade. I'm a Sig Op, and most other trades are far more physical than Signals, however, we hold the same standards as everyone else, and I am a firm believer in abolishing the double standard. Yes, there are some women out there that really don't give it their all, and quite possibly should not be in the military, but the rest of us do what we can to get rid of the stereotype.
In the end, if you try your best, and do what you can to contribute, no matter how big or small, or gender you are, you will look good to the boys and your superiors.
And yeah, if you aren't sure about it yet, work on your physical standard, and join the reserves....reserve males have a far more liberal view than reg males I find, and heck, if you don't like it you can get out, and if you really do like it, you can continue and either stay reserve, or join the regs...but don't let a bunch of stinky boys change what you want to do with your life!
Cheers,
Gilligan