Do you mean whenever you answer someone's questions? You can put your link as the "resource link". You do it manually for each question you answer. Try not to go overboard with it though or they may accuse you of spam.
yea for yahoo answers you definitely don't want to put more than two links for answer, usually only one. If you look spammy your gonna get banned. and you have to start every link with http:// or it won't work.
As mentioned above, just post the URL. If you're into a little BH, you can post your own question, answer it with another account and name your own site as a resource. Then, in a day or two, name your answer as the best. If you properly keyword your question title, you'll get the benefit of SE traffic. Warning: play with this tactic at your own risk!