I tried valerian capsules when I was an insomniac. It's really like fighting a dust storm with a broom. If your brain wants you to be up, for whatever reason (blah diet blah lifestyle...), it's going to keep you up. I remember only a few instances where it helped me sleep, but it started giving me night terrors, which has been a reported side-effect in studies, so I stopped. From what I read, there have only been a few studies on it's efficacy, and most of it's therapeutic value is described in folk medicine.
Another option is Kava Kava (Kava root.) My friends and I used to fill nalgene bottles full of the extract+water, which tasted awful, and bring them to work to make our dead-end jobs a little more tolerable. It relaxed us, made us a little more talkative. If you have a higher dose it will help you sleep without any side-effects or grogginess. It fulfills the social role of alcohol in some Polynesian cultures. There was some scare about it causing liver damage, but that was some isolated incidents from improper processing; cheap brands using other parts of the plant besides the root. You can order quality Kava from some places based in Hawaii.