a good way to start is with your local shops- and submitting to magazines-
with your local shops you can take in the sample quilt-and the patterns- sometimes they will buy them outright from you=sometimes they will sell them (commission style) for you- if you get some local interest going-then if they participate with other shops for shop hops you may be able to get the other shops to start carrying your patterns- it takes time- magazines that encourage/showcase new designers can really get you alot of exposure