Most (if not all) people who search with the intention of initiating a reunion have preconceived ideas about what the actual reunion will be like. This can either help to prepare them or set them up for a real disappointment. Do your best to let go of any 'fantasy' images you have of your birth relative(s).
Everyone will have different reactions to reunions, and these reactions can change over time. Take things one step at a time!
There are various ways of establishing contact, including on the phone, in a letter, via email, or in person. I chose to start with letters so that I could take all the information in at *my* speed, although I became so comfortable and so eager for more information, our contact quickly moved to the telephone, email, and eventually, personal visits. This is not to say that this would be the best route for you only you know what you're ready for.
You're going to meet...now what?
Making Contact via Phone
Making Contact After the Search
Five Stages of Reunion