Have you gone to the members section of the site:http://www.bellaonline.com/members/members.asp
Here you would sign in and then add favorite sites, not sure if the forum is considered one or not.
I just checked and it is a drop down menu listing all the sections of Bella, so you could do the ASD section and then from there you can click on the forum.
Or use the favorites of your computer program and click on to add. When you are writing in a thread you have the option of being notified of new posts and then that shows up in your favorites under "my home" in the forum section.
Hope this makes sense and helps out.