My ob/gyn recommended Rainbow Light Prenatal One. I did my research, compared a few, and chose to get those anyway. But if you have women around you that you can ask, it's always good to get their opinions. I just started mine, bought a small pack because, from what I read in reviews, it takes a while to get used to (for you to get used to it and how you like it) and then it may or may not be different also once you're pregnant (if your baby likes it or not). I like it so far, some women complained of the size or taste, but it is similar to my women's vitamin that I was taking before so it didn't bother me.View Thread
I've read it's better to start taking Folic Acid at least a month (or few months) before trying to conceive. I recently asked one of the webmd guest docs and she said that the prenatal vitamins are great vitamins in general anyway - so it's not a bad idea to start taking them early.
"Most important, make sure you've started taking 0.4 milligrams, or 400 micrograms, of folic acid a day. Folic acid taken a few months before conception has been shown to dramatically reduce the likelihood of neural tube defects, such as spina bifida."