If you have a website, then you can become an online travel agent and/or an online travel consultant.
First, you should include travel content. There are many travel articles that you can reprint on your website. You can also write your own travel content.
Join Amazon.com's associate program and include books on travel that your website visitors can purchase.
Then, you should have a travel portal. Sign up for The Reservation Company, which allows travelers to book travel from your website. You get a percentage as affiliate commissions.
You can also sign up for Book Vegas, Book Hawaii, and Book Maui.
Research other travel affiliate programs. You can find many travel affiliate programs at Affiliate Showcase, AffiliateShowcase.com/?58682.
You should also sign up for a hotel affiliate program, such as Hotel Express.
Keep up-to-date on travel information, travel tips, and travel news that you can post on your website.
You can also include a portal where visitors can ask questions on travel.
If you sign up at bravenet.com, then you can also have a travel forum. There are many other webmaster tools you can sign up for such as classified ads, etc.
Study other travel websites and take notes on how you can improve your travel website.
With this information, you can start your own online travel agency.