The first place to start looking for information on resumes, letters and interviewing is the CDC's Job Search Handbook. After you have looked at the handbook try these links:
US Department of Labor: Employment & Training Administration H1-B Disclosure Info
The US Department of Labor is required to provide a list of those employers who have asked for H1-B visas for employees. Search this database to find which organizations have sponsored H1-B visas in the past.