A traffic exchange is a site where you can get new visitors to your web site in exchange for viewing the sites of other members. More commonly "You view my website, and I'll view yours".
Click 'Surf' on the members area menu to start viewing sites from other members. You will earn credits for every site you view. Your site will receive one hit for each credit that you assign to your site. If you upgrade you will get more credits per view.
If you can't log in, it is usually because either your username or password is incorrect. It could also be because your account is unverified, or that you have been temporarily blocked because of too many login attempts. If you get another error or need help specific to your account, please contact support.
To have a profile picture, you have to use Gravatar, Globally recognized avatars. Sign up there with the email you use for your account here, or add this email to your existing Gravatar account. Connect a picture to it and rate the picture "G" as in suitable for all ages.
Promote any of the links listed on the Affiliate Toolbox page under the Affiliates menu. When someone signs up from your link, they will be your referral. You will earn credits when they surf and commissions when they purchase something.