Careers
Job Boards
American Society of Travel Advisors (ASTA)
American Hotel & Lodging Association
Hospitality Sales and Marketing Association International (HSMAI)
Travel Writing & Photography
I've toyed with the idea many times but, never taken the leap. Below are some resources.
Freelancer
Other
Visit any travel industry supplier website (e.g. airlines, hotels, cruise lines, air lines, tour operators, etc.) and you’ll find a careers section where you can browse available job opportunities. Also, job search sites (e.g. Career Builder, Indeed) usually have some search options along the lines of "travel, hotels, cruise lines" to show you travel industry-related jobs.