Question about assigning contract to investors


I have some quick questions about assigning contracts to investors. I’m just missing a few pieces to the puzzle.

Once I have the purchase agreement signed by the seller and I have an assignment agreement signed by the investor. Do I give the investor the original purchase contract along with the original Assignment Agreement and I keep a copy? Or, do I give the investor the copy and I keep the originals?

Question #2
Once I have the assignment contract signed by the investor, do I tell the investor that we close with my attorney? And if so, do I send a copy of my contracts to my attorney for setting up the closing or do I send them to the investors attorney?

Question #3
Do I order a title search or does the investor handle all of that stuff from this point forward.