It's tricky and lucky for you I fiddled with it long enough to get it figured out.
First, you have to find our servers, this is the hardest part as their is no good filter options to help us find ours. No search option as of yet.
You will have to find NFOservers.com: GeezerGaming #! , #2 and #3. Usually if you find one, the others are close by.
Once you find one of them, highlight it and hit "Server Details". Once on that screen, look in the lower right corner and you will see a STAR. Click the STAR and it turns YELLOW in color denoting that is now a "FAVORITE".