Prenatal vitamins & folic acid

Tara • Happy wife and mother to a beautiful baby girl born 09/15!
Hi ladies, 
​  I was wondering does anyone know how long before you get pregnant or try to get pregnant should you be taking prenatal vitamins and folic acid?  My husband and I will be trying here before you know it and I want to make sure I do everything I am supposed to do. I know I need to be working out, eating healthy, no drinking (while trying), and overall being healthy. But unsure about those vitamins. Also if anyone knows any great brands please let me know. Thank you so much for your help!