A lot of people have found help in the book "Raising Boys" (I think that's the title) by Dr. James Dobson. It explains and discusses the various ways to rear boys in today's society. In other words; how to raise a gentleman, how to avoid/deal with homosexuality, etc. I have tried reading it several times, but with two boys of my own, I barely have time. I should've read it before my boys were born. I, too, have only 1 sister and no brothers, and had no friends growing up that were boys. I lived what you call a "girly existence" LOL. Even my mom, when she came to help, said she didn't know how to diaper boys...she kept getting a shower. LOL Obviously, it doesn't take long to learn. And as far as you stumbling along...lots of us are stumbling along, and continue to stumble cuz even with two boys, they're SO different, and I'm expecting a girl in November!
Oh, btw, my second son was proud of being a boy in the ultrasound too. But we found out why after he was born...he has club feet. He was basically sitting on the bottoms of his feet, with his knees apart, therefore making it easy to see his genitals. With this third pregnancy, the tech made sure to get pics of her feet to be sure they weren't clubbed. You may want to see what your OB thinks of this. (Club feet isn't that tragic, but it takes getting used to. He had to have casts on his legs for 7 weeks straight as a newborn. He's 16 months now and still is required to wear special shoes and a bar between them at night.)
Hope that helps! -A.