Spousal support is designed to assist a party in maintaining the marital standard of living. Called "alimony" in many states, and in California until 1970, spousal support is not governed by a formal guideline. If fact, judges are prohibited from using "guidelines" in setting long term support.
Temporary support is designed to maintain the status quo until the property is divided. Long term support [also called "permanent" or "judgment" support] is designed to last longer and takes into account many different factors. The key factor is the standard of living of the parties during the marriage. An informal guideline has been developed in San Diego, although it is not applied in all situations.
In setting either temporary or long term spousal support, judges are usually limited by the amount of income coming from both parties. In most cases, it is impossible for both parties to maintain the marital standard of living after separation. Contrary to one popular myth, the person who receives support is not "entitled to maintain the marital standard of living" - that standard is one factor, but the availability of income is usually a limiting factor in setting support.
In California, it is the goal that each party make reasonable efforts to become self-supporting. This is a very flexible standard, dependent on many factors, not the least of which is the opinion of the judge assigned to your case. In deciding whether a party has used those efforts, the court can consider evidence of his or her earning capacity, and order support accordingly.
Spousal support is set from the income available after Child Support is set by the court. Because there is no guideline for setting support, a Certified Specialist can give you the best idea whether support will be ordered in your case, and how much.
Spousal support is a phrase for what many other states call "alimony." California changed the designation in 1969, hoping to give it a better connotation. At the same time, Divorce was renamed Dissolution of Marriage. Changing names does not seem to have much effect.