Glad you asked...
Include everyone who is being welcomed in the speech. You want to tell why they are there, their names and the reasons why you are welcoming them. Make it beautiful and be sure not to forget anyone!
Then again, this answer might help you...
A welcome address is similar to a welcome speech, but is usually longer. Basically you will follow the three main parts of a speech, which are the beginning, the body and the closing. The beginning often contains a joke or ice breaker. The body tells them what you need to tell them, and the closing thanks them for coming.

