College Plus: How it Works.
Their official "info packet".
Webinars on a range of topics...
...and eBooks on even more of them!
Finally, an extensive (and informative!) recorded webinar plus a couple of extra videos. Their YouTube Channel is an interesting browse as well.
If you're taking the plunge into dual enrollment, log into the forums before you start buying homeschool resources... there's an active used curriculum section!