I have a similar situation with light, and I am able to grow my herbs rather slowly - which for me is better than nothing at all. Some herbs need the heat of the warmer months, however many will be able to make it through your zone 8 winter. I'm in zone 9, and I can keep most of mine going all year round. If you already grow veggies successfully, then you should do fine with herbs too.
Woody perennials like rosemary and sage will need a bigger space - it might be better to find a spot in the ground for them, and save your bed for the smaller ones.
Some easy annual herbs to start with are parsley, cilantro, basil, oregano, and thyme (perennial). I'd suggest picking your favorites from your local garden center and giving them a try. You will soon find which ones do best in your particular garden.
The only herbs I've tried that haven't worked are chives and french tarragon. Those seem to really need more light. My texas tarragon does great though.