member_start and member_complete

[psixtynine]

Hi, i'm still learning about how the vb system works, hooks, templates and such.
What's the difference between member_start and member_complete? I'm doing something as simple as getting the usernotes to show up on a member's profile.
I added a hook on member_start to query the usernotes table for that specific user, What I don't get is the difference between those member templates, and how to print out each usernote. Another thing, is it possible to let users put in html but have all that input parsed to bbcode? like if they entered <b> it'll automatically change to [b] and javascript tags won't be chagned to anything because there is no bbcode?

Thanks