You should read this thread, it will help out with some questions you have:
AsiaJam AffiliateBot
Also this thread:
For beginners
It's easy to understand after you have read those threads. It made sense for me after I read them.
For the sign-up page, just fill in the appropriate fields and choose "personal" unless you really are signing up for a business one.
For the website section...it's all optional. If you have a website just fill it in regarding your website.
For the mailing/newsletter section it is only if you have members that you can e-mail offers to or etc. Meaning you have access to their e-mails.
Hope that helps and if there's things you still don't understand, just post away! lol