Most small businesses wait till it is to late to hire a lawyer, meaning they are already getting sued. Hiring a lawyer at the point were your company is already sued puts him as well as the company in a weaker position from the start, decreasing the chances of winning a court case. Furthermore there is no chance to avoid the sueing before it even happens as a good attorney is maybe able to.
Also having a good lawyer in your company basically gives you a flatrate on legal questions.
For example:
He can help you formulating contracts either with you employees or/and your consumers.
Help with taxes, maybe you are able to save a lot of money without knowing it.
If you are in the media intellectual property is absolutley crucial, but do you know the exact laws?
Wether you are a big or a small firm isn´t important at all a lawyer is a must even if he is not employed with your company and only in a consulting position he/she will help you a lot in your daily business life.