In looking for a Coven, you need to think about a couple things.
1. What type of Magick interests you; are you interested in working more with the elements, divination, shamanism, Satanism, spirits, blood magick, voodoo/hoodoo, everything in general, etc.
Once you have this figured out, then you need to dig through the Covens we have on this site looking for those that have your interests. Upon making that list, now you have something else to look at:
1. Are they accepting new members?
2. If you are a beginner, are they accepting beginners?
3. Do they have a specific application process other than just clicking the join button?
4. If they have a membership rule list, read it. Can you follow these rules and be an active member?
Usually by this point you have between 1-3 Covens to choose from, next step would be contacting the Priest, Priestess, Council, and maybe some of the members. Ask them what they think of their Coven; or what they have to offer. Compile their responses and weight out your decision. Usually if you spend at least a week thinking and asking questions, chances are you will end up in the Coven that you will remain in for some time. ;)
After you get into your new home, take it upon yourself to introduce yourself to everyone. And while doing so say a little about yourself, and the fact that you would be thrilled in someone in the Coven could take you on as a student. From there one should find you. And be patient and positive. All things take time, plus you'll appreciate it more if you don't rush it. ;)