Can my previous employer limit or regulate who I go to work for including a competitor?

You can't use any trade secrets belonging to your former employer in your new job.  Whether or not particular information constitutes a trade secret, however, is always debatable.  It depends on such factors as the degree to which the information is secret (information which is publicly available or can be readily ascertained is not a trade secret), the amount of time and/or money which the employer expended to develop the information, the effort expended to keep the information secret, the degree to which the employer derives a competitive advantage from the confidentiality of the information, etc.  Thus, for example, a customer list which anyone can derive just from looking in the yellow pages or buying a list of subscribers to a trade publication is not a trade secret, while one which a business has compiled over a period of many years, at great expenditure of time and money, which the business goes to great lengths to keep secret by limiting access to only high level employees, and which is not readily ascertainable by others, probably will be considered a trade secret.