I myself havent bred anything as of yet but im researching as much as i can before i do. I dont want to make just any old cross, nor sterile babies. There seems to be alot involved if you want the progeny to be superior. I havent come across any such web sites but when looking at genus names you can tell what they have bred with....within this forum there is a list of genus names and there mixes OrchidTalk Orchid Forums - Grow Orchids! RVO's Orchid Genus Listing......also if you look at online encyclopedias for species you can find what family they are in....for example.. Phalaenopsis, Cattleya, Paphiopedilum, and Dendrobium are all in separate families and cannot be bred together. Maybe some experts will tune in soon. If you have a question about a specific two that you want to breed then just post a thread. Im sure someone will answer.