Donations - You can donate to the forum by clicking http://www.blackhatworld.com/blackhat-seo/payments.php. It usually takes an hour for your status to be updated on the forum, after you donate. If more than 2 hours have passed and your account has not been upgraded, please just send me a PM.
Signatures - In order to have text, images or html in your signature, you have to be a Donor. As a Donor, you may post 1-2 affiliate links and 1 small banner in your signature. Do not use a font size larger than 3, large images, sound clips, or anything annoying. We reserve the right to change, delete or rearrange your signature as we see fit.
Check this thread out to know more about the membership levels: http://www.blackhatworld.com/blackhat-seo/forum-suggestions-feedback/371541-all-about-bhw-membership-levels.html