Some Helpful Links

If you're beginning your own journey to reunite with a birth parent, sibling or adopted child, or birth relative, the first thing I would suggest is that you register with several registries and support groups. I recommend that you get yourself organized with a 3 ring binder include in it information on all of the registries that you signed up on with your dates of signing up and followups. Also include a list of contacts, including the dates you made contact.
This first registry I suggest is the International Soundex Reunion Registry (ISRR). This is a non-profit, "mutual consent reunion registry for persons desiring a reunion with next-of-kin". That means that they have a data base of searches and when there is a match, they notify the parties of the match. This is the largest of the registries and have had matches from all over the world. There is no fee for this registry, but they do appreciate donations.
Their site can be found at: http://www.isrr.net/faq.shtml
The next registry is the Adoption Data Base. Again, this is a non-profit registry that notify you when they have a match. But beyond that, they also have a search and support group that is chock full of really nice helpful and supportive people. Their Search Angels have many success stories, and I found the support of the group to be very uplifting when I hit my lowest points. They also offer a No Find, No Fee Dedicated Search. This means that if you rather they do the searching, you give them a $25 Enrollment Fee and pay nothing more unless they "find", then you pay a low flat fee of $175. That's really not expensive at all when you consider that PI's get thousands of dollars for doing the same thing. They too charge no fee to sign up on the registry, but they also appreciate donations to cover the costs of keeping the site up and running.
They can be found at: http://www.adoptiondatabase.org/
Also, register with Adoption.com. This is also a free registry with over 300,000 records. You can register your information and also search to see if anyone is looking for you on this site.
If you were born and/or adopted in New York, I urge you to sign up with NYAdoptees. This is a group of members of the adoption triad who are dedicated to helping us all find our family members. This group is very well organized and can provide sound, helpful advice on navigating the cumbersome laws around adoptions in New York State. They are huge advocates for Adoptee's Rights. More than that, their Search Angels bend over backwards to help in searches. This group is also very supportive for anyone in the adoption triad. They can be found at: http://groups.yahoo.com/group/nyadoptees/
If you were born and adopted in NY State, go to the New York State Adoption Registry and download, print, fill out and mail in your registration. This is a mutual consent registry maintained by the New York State Department of Health. If they have a match, they will send each party a consent form that must be returned to them before they can release any information. If you are looking for a sibling who was born and adopted in NY, fill out the sibling form.
That's all for now, I will add more as time permits