Each state has various employment laws affecting human resources. John F. Buckley's State by State Guide to Human Resources Law (Aspen Publishers) is a good way to locate them. Alternatively, check out the the statutes, regulations, legal encyclopedias and/or treatises relevant for each individual state.
The TRAVAIL Database of Conditions of Work and Employment Laws explains "the regulatory environment of working time, minimum wages and maternity protection in more than 100 countries around the world."
For the inside information on a company's employee-relations, check out the Vault reports. Vault interviews former employers to compile reports on major companies, including the big law and accounting firms. Also see Glassdoor, which posts comments from current and former employees.
To get sample job descriptions, check out The BLS's Occupational Outlook Handbook and/or an online job board, such as Monster or CareerBuilder. You can also check out the "help wanted" sections of relevant print or online newspapers.
Non-competition clauses and agreements: Employment agreements often contain clauses limiting the employee's ability to compete with the employer after the employee leaves the company. In some cases, these provisions are contained in a free-standing agreement. The leading treatise on non-complete laws is Covenants Not to Compete: A State-By-State Survey (BNA). Other sources: Employment law treatises for the state(s) in question, and legal encyclopedias for the relevant state(s). The Practical Law Company provides a summary of the relevant laws for many states (subscription only).
International Assignment Agreements: An International Assignment Agreement (IAA) or Expatriate Assignment Agreement (EAA) describes the terms of an employee's assignment when working outside of his or her own country.
You can find model Agreements attached as Exhibits to SEC filings (see SEC Filings) or just use Google or another search engine.
For guidance drafting an IAA/EAA, see Chapter 11, "Structuring the Expatriate Employment Agreement" of the International Human Resources Guide (West). See also Structuring International Transfers of Executives (Thomson/RIA).