In order to place a photo request you will first have to create an account. Simply fill out this form and you will be sent an email to verify your email address.
Once you have verified your email address you will be able to post your photo requests. You will also be able to edit your account details, upload a company logo, as well as contact photographers directly.
If you wish to sell and buy photos you may do this by logging in to your account and setting your account type to Buyer/Seller.