Each state has their own procedure for divorce. The majority of states adopt the "no fault" approach to divorce, while some retain a "fault" divorce system.
Getting a legal separation may be the first step when seeking a divorce. If spousal abuse, domestic violence or threatening behavior is an issue, a restraining order may be necessary. Spousal support or alimony are also issues that may be best resolved in your favor when handled by an attorney; who may also be necessary if there is a need for an enforcement decree. Any prenuptial agreement you may have entered into could also have a bearing on your divorce settlement.
If there are children there may be child support, child custody or child visitation issues to be worked out as well. Mediation is another possible solution for resolving marital issues that is used by many couples.