If this is the first time that you've done any real hair management down there, I would suggest trimming your pubic hair first. If you go right in with a razor, you will be yanking a lot of hair out and irritating your skin like mad.

After you trim, I would do different parts of your vagina every day leading up to your "sexual debut". This will give you a chance to learn the curvature of your vagina and lessen the opportunity of your skin getting really irritated. Start with the mound above, then maybe the bikini line another day, and finally the labia. Be sure to use some nice, thick shaving cream to prep the skin and a BRAND NEW RAZOR. Never a dull or even a day old one. The skin down there is way more sensitive than say your legs. As far as technique, I shave similarly to how I do my leg. The only real difference is I use smaller strokes.

My biggest thing is after care. I use Nivea's Post Shave Balm for Sensitive Skin after patting everything dry. It helps a ton with preventing bumps and marks and such and my skin always just looks so happy. :)

Good luck, girl!