I did this soley in Vegas by editing several videos I had done pic in pic in: (and I know the video is obnoxious, I was just seeing how many videos I could sqeeze in before I got bored)
Media Generators / Credit Roll. Choose the preset closest to what you want and drag it to the timeline. A window pops open to allow you to enter text. In the middle of the top of that window is a duration. Change this to your best guess of how long you want the credits to run. It defaults to 10 seconds, which is pretty short. After changing the duration drag the credit roll clip on the timeline out to match that length.
Enter the text you want on the credit roll.
Just a thought, but you might want to try glancing at the help pages. You'll probably find a lot of these answers there faster than waiting for someone to respond to you in here. :)
Thanks for your answer, is it possible to hold on the title at "Plain Scrolling on Black" for a few seconds, like to hold on the credits in between? I can use a text generator, but maybe there is a better way...?