How do I create a website and prevent my corporation from owning the rights and intillectual property?

If your employer does not have an agreement with you providing that your employer has ownership rights in anything that you create or invent, and if you do not use your employer's property or resources to create your website, and if your website does not contain anything that belongs to your employer, then your employer probably will not have a valid basis for claiming ownership in your website.

The question appears to lack sufficient definition. First of all, why would your employer have any rights to your website? Absent a prior agreement/contract and/or performing website work on your employer's time, I see no basis. Of course you have no right to publish any confidential info or materials that may be copyrighted by your employer (absent express permission). Secondly, apart from any issue of legal rights, I assume you would not want to antagonize your employer. Is this the more concerning issue? Third, California's laws protect what employees do using their own resources and on their own time. You're welcome to get in touch or post further. Based on your posting, an initial question would be the basis and undercurrents relating to your concerns.

You need to have an intellectual property attorney look at your employment agreement to have a good idea about how that will work for you. Everything can turn on a single sentence in that agreement.