I don't believe either my DH or I were tongue tied either (neither one of us was nursed as babies ) but my mom remembers getting something clipped when she got her dentures (at an early age) so she might have been tongue tied (but was breastfed I believe). We figured out that my DD was tongue tied because 1. nursing was horrifically painful and my nipples became damaged very quickly, 2. Her tongue was heart shaped when she cried. 3. My supply was in trouble, she had low weight gain, and the ped wanted me to supplement (but told me tongue tied did not affect bfing, yeah right).
Dr. Sears kind of outlines the tell tale signs in the baby book. I had a hard time finding someone who would just clip it though without wanting to put her under GA in the hospital. Then i found this doctor: http://twofloridadocs.com
She has an article on tongue tie on her website that you might find informative.