Speaking only about the legal angles, the first question is, what is your position in the company and what is hers. If you are an owner, stockholder or shareholder, or high level executive and she is not also on the same level as you are, it's a
very bad idea. If you are both lower on the totem pole, does your company have a policy against dating? If not, so much the better. If so, look carefully at it and see if it prohibits this relationship. It may or it may not. If there is no policy, and you are both on relatively the same level, and not too far apart in age, it's not risk free, but it's probably very low risk unless you do something dumb.
First rule of not doing something dumb is, if she says "No," that's it. Don't push it. Second rule is don't do something on the company's time that you wouldn't tell your grandmother about. After hours, have at it, though avoiding a hit and run is excellent advice. If you're going to fuck a gal over, you probably shouldn't. And for the love of God, don't do that to a co-worker. Just bad form and dumb in more ways that you can shake a stick at.
One final thing to consider, how good is your job. If it's a McJob that you can replace in a week or so with a job that's just as good, you can take more risk. If getting fired would be a life altering event and you might never recover from, it's always best to err on the side of caution, no matter how safe you think you are.
Now, on a more practical level, ask her if she wants to go out for pizza and then go fuck afterwards. If she says, "No!," ask her "What's wrong? You don't like pizza?!"
Seriously, follow policy, just be generally respectful, don't date folks way above or especially below your level, and use common sense. You'll probably be fine.
