$30

next project link

on my site, karenmessing.com there are 3 pages that contain multiple posts. i am building a child theme using thematic.

i need help fixing the next project link that appears on each individual post page, ex: http://karenmessing.com/?p=55.
i want the next project to link to the next post within that category, for example from http://karenmessing.com/?p=55 i want the next project to link to this post
http://karenmessing.com/?p=27

at the last post in the category i would like the "next project" link to be "print projects" (to link to the next page posts).