Buy a complete B complex which includes folic acid and biotin. The one I use also contains some vit C. Take with breakfast and dinner. Dosages are same for both genders, and not especially important after some point - you don't need a huge amount and will piss away the rest.
Don't expect to feel much unless you are actually deficient in something. You can probably just use a good multi like OrthoCore taken several times a day.
If you want an energy supplement, look into carnitine + lipoic acid, together with CoQ10. Some people like carnosine or beta-alanine. Don't expect miracles from supplements.