Circuit Breaker Keeps Tripping?

You are on the right track.

I would always recommend a qualified electrician to troubleshoot such a problem.

Removing loads to eliminate possible problem loads is a good start and usually identifies the problem. Make sure all loads have been removed from that circuit.

What an electrician would do is make sure all wires from each removed fixture are isolated with wire nut or tape. Then go to a receptacle nearest the panel and disconnect the hot wire which should be black and connects to the brass colored terminal.

He/she would not disconnect at the terminal, but separate at the wire nut because this feeds the other loads down stream. After isolating with wire nut or tape, they would go back to the breaker to see if it stays on. If it doesn't, the problem is between the breaker and receptacle. If it does stay on, the breaker is turned back off and the receptacle is re-installed and the electrician moves to the next receptacle until the problem is found.