I really think that Avon is a fabulous publisher of historical fiction – which makes it pretty hard to get a book accepted there. You can’t do it without a literary agent; Avon doesn’t take novels from the slush pile. So you need to find an agent. My first suggestion is that you join the Romance Writers of America. They have monthly meetings and a monthly magazine with loads of great information about agents and publishers — they do interviews with agents almost every month. Another thing you could do is watch out for a contest in which the final judge is an Avon editor. I know several people who’ve got published by winning contests. Good luck!