Finding salary and compensation packages for specific named individuals is difficult. For private companies there is no reporting structure to make that possible. However, there are avenues for finding information on executives at public companies. The compensation packages for public companies are included in the form filed with the Securities & Exchange Commission (SEC) usually referred to as a Proxy. There are also cases where 8-K filings including compensation information for top executives, particularly as it results from any changes to compensation packages. These filings can often be found on a company's Investor Relations page or through the SEC.
For anyone looking for lists of top-paid executives in a particular sector or researching trends for top executives, there are various lists published by trade publications and news sources either regularly or as a occasional pieces. A few examples are listed below.
Also, while they aren't corporations, if anyone is interested in compensation for top employees at non-profits, the 990 form filed with the IRS is good for general information about the non-profit including executive salaries.
One last option for research is to use sources like Indeed.com or other sites that list jobs. These sites would be good for understanding the salary in a particular place for a particular job, but also may help to understand what any additional qualifications like certifications, languages, and skills may command in terms of salary.